google-query-parameters.txt

aasb = Unknown
action = Unknown
ad = Unknown
addh = Unknown
adsafe = Unknown
adtest = Ads test mode (when adtest=on, Google treats the query as a test so ad impressions aren’t counted)
adtest-useragent = Unknown
aec = Unknown
aep = Unknown
affdom = Unknown
agsabk = Unknown
agsad = Unknown
aioh = Unknown
ais = Unknown
akm = Unknown
amp = Unknown
ampcct = Unknown
ampidx = Unknown
ampru = Unknown
amps = Unknown
app = Unknown
appent = Unknown
aqs = Assisted Query Stats (used for logging autocomplete suggestions, appears when searching via Chrome omnibox) (Not confirmed)
ar = Unknown
arqrcd = Unknown
arv = Unknown
as_author = Unknown
as_drrb = Unknown
as_dt = Unknown
as_epq = Advanced Search: exact phrase
as_eq = Advanced Search: none of these words
as_filetype = Advanced Search: restrict to specified filetype
as_ft = Advanced Search: file type filter mode (i or ex for include/exclude)
as_maxd = Unknown
as_maxm = Unknown
as_mind = Unknown
as_minm = Unknown
as_nhi = Advanced Search: numeric range upper bound
as_nlo = Advanced Search: numeric range lower bound
as_nloc = Unknown
as_nsrc = Unknown
as_occt = Advanced Search: where the terms occur (title, text, URL, links)
as_oq = Advanced Search: any of these words
as_q = Advanced Search: all these words (equivalent to q)
as_qdr = Advanced Search: results timeframe or date restriction
as_rights = Advanced Search: usage rights filter (e.g., cc) (Not confirmed)
as_scoring = Unknown
as_sitesearch = Advanced Search: limit results to a site or domain
as_st = Unknown
asid = Unknown
asift = Unknown
atp = Unknown
atvm = Unknown
authuser = Unknown
avx = Unknown
bav = Unknown
bih = Browser internal height (the height of the browser window in pixels) (Not confirmed)
biw = Browser internal width (the width of the browser window in pixels, sent by the client) (Not confirmed)
bmp = Unknown
br = Unknown
brd = Unknown
bret = Unknown
bs = Unknown
bshm = Unknown
bshope = Unknown
bsp = Unknown
bsq = Unknown
bvm = Unknown (possibly a tracker for browser version or location) (Guess)
c2coff = Unknown
cad = Unknown (possibly an affiliate, referral or client token) (Guess)
canvasid = Unknown
capabilities = Unknown
cct_optout = Unknown
ccurl = Unknown
cd = Result rank index (the position of the clicked search result, e.g., cd=3 for the 3rd result) (Not confirmed)
cds = Unknown
cf = Unknown
cfsqs = Unknown
changed_loc = Unknown
channel = Channel/context identifier for the search (e.g., “fs” for Firefox search plugin channel) (Not confirmed)
chips = Unknown
chrq = Unknown
clie = Unknown
client = Client application identifier (indicates which app or browser made the search, e.g., “firefox” for Firefox’s search bar) (Not confirmed)
cmpsr_imgurl = Unknown
cmpsr_name = Unknown
coie = Unknown
complete = Unknown
convo_fpr_esc = Unknown
corpus = Unknown
cp = Unknown
cr = Country restrict (limits results to pages from specified country region(s), e.g., cr=countryUS)
cs = colour scheme (0 = light, 1 = dark)
csst = Unknown
csui = Unknown
csuio = Unknown
csuir = Unknown
ct = Click type or location (indicates where on the page the result was clicked) (Not confirmed)
ctb = Unknown
ctf = Unknown
ctsctx = Unknown
ctxs = Unknown
ctzn = Unknown
data_push_epoch = Unknown
dbl = Unknown
dcntid = Unknown
dcr = Unknown
ddl = Unknown
deb = SERP debug parameter for internal use. Enables various internal debug overlays. Different numeric/alpha variants switch on different debug channels # Pedro Dias
debtime = Unknown
depid = Unknown
devicelang = Unknown
devloc = Unknown
docid = Unknown
domains = Unknown
dpl = Unknown
dpr = Unknown
dq = Unknown
dr = Unknown
ds = Unknown
dthp = Unknown
duul = Unknown
e = Unknown
ech = Unknown
edbg = Unknown
editnurl = Unknown
editourl = Unknown
editq = Unknown
editrt = Unknown
eeui = Unknown
ei = Search query ID (an alphanumeric ID for the session/query, encodes a timestamp and other data for internal tracking) (Not confirmed)
elrc = Unknown
entrypoint = Unknown
eqld = Unknown
ertn = Unknown
espv = Unknown
esrch = Unknown
eval_id = Unknown
exam_sel = Unknown
exam_tab_sel = Unknown
exam_tier_id = Unknown
exam_vid_cat = Unknown
exp = Unknown
exp_uid = Unknown
expflags = Unknown
expid = Unknown
expid_c = Unknown
explain = Unknown
expnd = Unknown
exprollouts = Unknown
fakeads = Unknown
fbs = Unknown
fbx = Unknown
fbxst = Unknown
fc = Unknown
fcq = Unknown
fcv = Unknown
fesp = Unknown
fheit = Unknown
filter = Duplicate filter toggle (controls filtering of similar results; 0 = show duplicates, 1 = filter duplicates)
fir = Unknown
flav = Unknown
flbr = Unknown
fll = Unknown
fp = Unknown
frcnw = Unknown
frendfilter = Unknown
frozen_clock = Unknown
fshp = Unknown
fspn = Unknown
fsr = Unknown
fstat = Unknown
fz = Unknown
garc = Unknown
gbpv = Unknown
gbv = Google Basic Version flag (controls use of a basic HTML version with no JavaScript; e.g., gbv=1 for basic mode) (Not confirmed)
gc = Unknown
gcc = Unknown
gcs = Unknown
gib = Unknown
gko_vi = Unknown
gl = Geolocation country code (boosts results from a specified country, e.g., gl=US for United States)
gll = Unknown
glslf = Unknown
gm = Unknown
gpc = Unknown
gr = Unknown
gs_id = Unknown
gs_ivs = Unknown
gs_l = Unknown (likely indicates the search context or type, such as web, image, etc.) (Guess)
gs_lcp = Unknown
gs_lp = Unknown (contains combined info like the search query and client in a single parameter) (Not confirmed)
gs_mss = Unknown
gs_ri = Unknown
gs_rn = Unknown
gs_ssp = Unknown
gsas = Unknown
gsc = Unknown
gsessionid = Unknown
gstk = Unknown
hci = Unknown
hgi = Unknown
hl = Interface language (UI language of the search page, e.g., hl=en for English)
hlvts = Unknown
host = Unknown
hotel_dates = Unknown
hotel_ds = Unknown
hotel_lqi = Unknown
hotel_lqtkn = Unknown
hotel_occupancy = Unknown
hotswaps = Unknown
hpcs = Unknown
hq = Unknown
hs = Unknown
htf = Unknown
htin = Unknown
htpt = Unknown
hts = Unknown
htssns = Unknown
htst = Unknown
hw = Unknown
iar = Unknown
ibp = Alternative render mode (alters how certain content is displayed, used for special page layouts) (Not confirmed)
ictx = Unknown
ie = Input encoding (character encoding of the query, default UTF-8)
ig = Unknown
igu = Interface mode (Ignore Google User" basically ignoring cookies and user consent an be used to logout without really logging out) // Valentin Pletzer
imgcolor = Unknown
imgil = Unknown
imgrefurl = Unknown
imgsz = Unknown
imgtype = Unknown
imgurl = Unknown
imgwo = Unknown
inlang = Unknown
inm = Unknown
interests = Unknown
ion = Unknown
iosla = Unknown
ircip = Unknown
is_shopping_entity = Unknown
isc = Unknown
isn = Unknown
ix = Unknown
jbr = Unknown
jfr = Unknown
jlsg = Unknown
jrt = Unknown
jsmode = Unknown
jspept = Unknown
jspt = Unknown
jsti = Unknown
kapk = Unknown
kgmid = Knowledge Graph ID (specifies a Google Knowledge Graph entity to fetch results for, can override the query term) (Not confirmed)
kgs = Unknown
kptab = Unknown
last_qid = Unknown
lcif = Unknown
lei = Unknown
lep = Unknown
lfid = Unknown
lid = Unknown
lite = Unknown
llpbb = Unknown
llpgabe = Unknown
llploc = Unknown
lns_aid = Unknown
lns_iis = Unknown
lns_img = Unknown
lns_int = Unknown
lns_mode = Unknown
lns_surface = Unknown
lns_tqs = Unknown
lns_vfs = Unknown
lnsid = Unknown
lnu = Unknown
lpis = Unknown
lpsid = Unknown
lqi = Unknown
lr = Language restrict (limits results to pages in specified language(s), e.g., lr=lang_en)
lrad = Unknown
lrfsid = Unknown
lsa = Unknown
lsack = Unknown
lsessionid = Unknown
lsf = Unknown
lsft = Unknown
lsisr = Unknown
lsspp = Unknown
lsthwfi = Unknown
lstodlfi = Unknown
lsts2b = Unknown
lsts2c = Unknown
lstsd = Unknown
ltkn = Unknown
ltype = Unknown
luack = Unknown
ludocid = Unknown
luul = Unknown
lxcar = Unknown
mactx = Unknown
madse = Unknown
mapsl = Unknown
masfc = Unknown
mat = Unknown
mc_action = Unknown
mc_qid = Unknown
mci = Unknown
mco = Unknown
mcp = Unknown
mcq = Unknown
mcur = Unknown
mdc = Unknown
mergelabel = Unknown
meta = Unknown
mfx = Unknown
mgtyp = Unknown
mid = Unknown
mlp = Unknown
mlrid = Unknown
mlro = Unknown
mlros = Unknown
mmorq = Unknown
mmsc = Unknown
mmsm = Unknown
mmso = Unknown
mods = Unknown
mq = Unknown
mrc = Unknown
mrq = Unknown
mrqei = Unknown
mrr = Unknown
msig = Unknown
mstk = Unknown
muul = Unknown
mvs = Unknown
mxt = Unknown
ndsp = Unknown
near = Unknown
nef = Unknown
nem = Unknown
nep = Unknown
newwindow = Open results in new window setting (newwindow=1 if user prefers results to open in a new tab/window) (Not confirmed)
nfpr = No auto-correct (if set to 1, prevents Google from automatically correcting spelling or showing corrected results) (Not confirmed)
nhr = Unknown
nirf = Unknown
no_sw_cr = Unknown
noa = Unknown
norc = Unknown
nord = Unknown
nossl = Unknown
nps = Unknown
npsic = Unknown
ntyp = Unknown
num = Number of results to display (e.g., num=50 shows 50 results per page)
nuul = Unknown
oe = Output encoding (character encoding for the results, default UTF-8)
og = Unknown
ogdeb = Unknown
ohl = Unknown
oi = Unknown
oll = Unknown
opi = Unknown
optaqua = Unknown
optd = Unknown
opti = Unknown
optq = Unknown
opts = Unknown
optt = Option toggler that can selectively disable specific ranking / UI components. # Pedro Dias
oq = Original query (the query text typed into the search box before using suggestions) (Not confirmed)
orcl = Unknown
ormc = Unknown
ormq = Unknown
orp = Unknown
ors = Unknown
orsc = Unknown
osm = Unknown
ospn = Unknown
output = Unknown
oz = Unknown
padb = Unknown
padt = Unknown
pbx = Unknown
pcmp = Unknown
pcr = Unknown
pcs = Unknown
pdl = Unknown
pdo = Unknown
pdoi = Unknown
peek_pws = Unknown
pei = Unknown
pf = Unknown
pga = Unknown
phdesc = Unknown
phets = Unknown
piis = Unknown
pjf = Unknown
plf = Unknown
plugin = Unknown
pnp = Unknown
pps = Unknown
pq = Unknown
prdl = Unknown
prds = Unknown
prmd = Parameter for suggested verticals (controls which vertical search options are shown in the interface) (Not confirmed)
prmdo = Unknown
prog = Unknown
psb = Unknown
psgn = Unknown
psi = Unknown
psj = Unknown
psoc = Unknown
pstick = Unknown
purs = Unknown
pvf = Unknown
pvh = Unknown
pvq = Unknown
pws = Personalization setting (controls personalized results; pws=0 disables personalized search results) (Not confirmed)
pwst = Unknown
q = Search query (the keywords or terms entered by the user)
qf = Unknown
qid = Unknown
qpaddr = Unknown
qr = Unknown
qsd = Unknown
qsubts = Unknown
quantum = Unknown
query = Unknown
ram_mb = Unknown
rapt = Unknown
rcid = Unknown
rciv = Unknown
rct = Unknown (possibly related to Google Ads click tracking) (Guess)
reamenities = Unknown
redays = Unknown
redir = Unknown
redir_esc = Unknown
ref = Unknown
reft_t = Unknown
remaxbath = Unknown
remaxbed = Unknown
remaxprice = Unknown
remid = Unknown
remids = Unknown
reminbath = Unknown
reminbed = Unknown
reminprice = Unknown
rendr = Unknown
reqflt = Unknown
rerect = Unknown
reresidence = Unknown
resnum = Unknown
restrict = Unknown
revid = Unknown
review = Unknown
rf = Unknown
rflfq = Unknown
rlakp = Unknown
rldimm = Unknown
rlha = Unknown
rlhac = Unknown
rlhsc = Unknown
rlla = Unknown
rllag = Unknown
rllas = Unknown
rlms = Unknown
rls = Client release/locale string (provides client and localization info, e.g., browser build and language) (Not confirmed)
rlst = Unknown
rlz = RLZ tracking code (used by Google to track Chrome/Toolbar distribution and marketing info) (Not confirmed)
rot = Unknown
sa = Search action indicator (represents user search behavior or action taken, exact purpose not officially documented) (Not confirmed)
sab = Unknown
sabf = Unknown
sabgci = Unknown
sabpf = Unknown
sabpi = Unknown
sabplaceid = Unknown
sabpnf = Unknown
sabvi = Unknown
sadv = Unknown
safe = SafeSearch setting (controls adult content filtering; “active” to enable filtering, “off” to disable)
safeui = Unknown
san_opt_out_data = Unknown
san_opt_out_request_mode = Unknown
san_opt_out_site = Unknown
sarq = Unknown
sbid = Unknown
sca_esv = Unknown
schips = Unknown
scis = Unknown
sclient = Search client (identifies the interface client, e.g., “gws-wiz” for Google Web Search wizard) (Not confirmed)
scoring = Unknown
scsr = Unknown
search = Unknown
sei = Unknown
sel_tier_id = Unknown
serdesk = Unknown
sert = Unknown
sesinv = Unknown
sessionid = Unknown
sfm = Unknown
shbud = Unknown
shdeb = Unknown
shem = Unknown
shmd = Unknown
shmds = Unknown
shndl = Unknown
shopbg = Unknown
shopmd = Unknown
shoprs = Shopping Graph base64 encoded data
shopst = Unknown
shortlistmids = Unknown
si = Knowledge Graph section indicator (used to load a specific Knowledge Graph tab or section in results) (Not confirmed)
sideb = Unknown
sidesearch = Unknown
siex_p = Unknown
sigct = Unknown
signc = Unknown
signedin = Unknown
sigpc = Unknown
site = Unknown
site_flavored = Unknown
sitesearch = Unknown
sjc = Unknown
sjcp = Unknown
skew_host = Unknown
skew_hotswaps = Unknown
skip = Unknown
sla = Unknown
sll = Unknown
smstk = Unknown
snopt = Unknown
sns = Unknown
sorc = Unknown
source = Source of the search (e.g., “hp” for homepage, indicates where the search originated) (Not confirmed)
source_ip = Unknown
sourceid = Source identifier (type of source or client that initiated the search, e.g., browser or toolbar) (Not confirmed)
sp = Unknown
sp_ae = Unknown
sp_aimrs = Unknown
sp_hpep = Unknown
sp_hpte = Unknown
sp_imghp = Unknown
spell = Unknown
spknlang = Unknown
spvr = Unknown
sqi = Unknown
src_amt = Unknown
src_curr = Unknown
srds = Unknown
srpd = Unknown
ssb = Unknown
ssi = Unknown
ssl_dbg = Unknown
sspn = Unknown
ssrs = Unknown
sssc = Unknown
sstk = Unknown
st = Unknown
start = Starting index of results (0-indexed offset for results, e.g., start=10 to begin from the 11th result)
std = Unknown
stefc = Unknown
stegc = Unknown
stegt = Unknown
stensi = Unknown
stent = Unknown
stept = Unknown
stick = Unknown
str = Unknown
strmmid = Unknown
sts = Unknown
sub_sel = Unknown
subcat = Unknown
subject_id = Unknown
sugexp = Unknown
suggest = Unknown
sugvcr = Unknown
superroot = Unknown
surl = Unknown
sxsrf = Security token (contains an encoded token and timestamp, likely for anti-CSRF or internal security) (Guess)
sz = Unknown
szl = Unknown
tab = Unknown
tacc = Unknown
tbas = Unknown
tbcp = Unknown
tbm = Search type (vertical search mode, e.g., tbm=isch for images, tbm=nws for news)
tbnid = Unknown
tbo = Toggles search tools visibility (e.g., tbo=1 to always show the search tools panel) (Not confirmed)
tbs = Search tools/filters parameter (used to apply filters like time ranges, e.g., tbs=qdr:w for past week) (Not confirmed)
tcfs = Unknown
tch = Unknown
tci = Unknown
tel = Unknown
tfs = Unknown
tok = Unknown
tr_d = Unknown
tr_dest = Unknown
tr_dest_latlng = Unknown
tr_dest_q = Unknown
tr_dest_st = Unknown
tr_or = Unknown
tr_or_latlng = Unknown
tr_or_q = Unknown
tr_or_st = Unknown
tr_t = Unknown
trnd = Unknown
tsdo = Unknown
tsq = Unknown
tt_class = Unknown
tt_date = Unknown
tt_destination = Unknown
tt_lcid = Unknown
tt_lfid = Unknown
tt_origin = Unknown
tt_pnr = Unknown
tt_pnr_src = Unknown
tt_pnr_src_id = Unknown
tt_quota = Unknown
tt_tn = Unknown
tt_trainnumber = Unknown
ttdexpref = Unknown
ttdif = Unknown
ttdrfmt = Unknown
ttsm = Unknown
ttsp = Unknown
twd_surface = Unknown
twd_tok = Unknown
twd_type = Unknown
uact = User action code (identifies the type of user action that triggered the search, value is numeric) (Guess)
ucbcb = Unknown
uclite = Unknown
udf = Unknown
udm = Universal Display Mode parameter for controlling the type of Google Search results shown (e.g., web, images, news, AI Overviews, etc.) // Ömer Evre
    // udm info from https://bsky.app/profile/hhackenbecker.bsky.social/post/3lrwcsksh7227
    udm=2: images
    udm=6: learn
    udm=7: videos
    udm=12: news
    udm=14: web
    udm=15: things to do
    udm=18: forum
    udm=28: shopping
    udm=36: books
    udm=37: products
    udm=38: videos (exact?)
    udm=39: short videos
    udm=44: visual matches (images?)
    udm=48: exact matches
    udm=50: ai mode
    udm=51: homework
    udm=56: cleaner results without extra flair
uds = Unknown
uid = Unknown
uideb = Unknown
ulrc = Unknown
ulv = Unknown
um = Unknown
upa = Unknown
useragent = Unknown
userid = Unknown
usg = Unknown (possibly an encrypted signature or token for the URL) (Guess)
utm_campaign = Urchin Tag Manager campaign tag for analytics
utm_content = Urchin Tag Manager content tag for analytics
utm_medium = Urchin Tag Manager medium tag for analytics
utm_source = Urchin Tag Manager source tag for analytics
utm_term = Urchin Tag Manager term tag for analytics
uuld = Unknown
uule = Encoded location parameter (encodes a specific location or latitude/longitude to localize search results) (Not confirmed)
v = Unknown
vacasync = Unknown
vaccardtype = Unknown
vacdatatype = Unknown
vachier = Unknown
vaclocmid = Unknown
vacper = Unknown
vactab = Unknown
ved = Encoded tracking info for clicked element (carries data about the result link or element that was clicked) (Not confirmed)
vgi = Unknown
vidcip = Unknown
vis = Unknown
vit = Unknown
vsdim = Unknown
vsint = Unknown
vsrid = Unknown
vuid = Unknown
wbsk = Unknown
wf = Unknown
wphc-agsa = Unknown
wrapid = Unknown
xhr = Unknown
zx = Cache-busting random number appended to requests (Guess)

Hi Mark,

Incredible work on compiling this list! It's an amazing resource for the SEO and tech community.

I've been conducting my own analysis of SERP interaction signals, especially concerning recent features like AI Overviews and client-side instrumentation (CSI). I've identified several parameters that seem to be missing from your Gist. They provide deeper insights into how Google tracks user behavior, accessibility, and engagement.

I thought they would be a great addition to your collection. Here is the list with my descriptions:

atyp (action type) - indicates a specific type of user action, e.g., a click
= csi - stands for "Client Side Instrumentation," a technique for collecting data on the client's side
= i (interaction) - "interaction"

atni (active tab navigation index) - a parameter used in the context of keyboard navigation, indicating the currently active element after the tab key has been used. Its changing value reflects which interactive elements the user navigates through using the tab key before making a selection (e.g., pressing Enter). It most likely monitors mouse-less accessibility

aqid (active query ID) - an identifier associated with a search query or session

bb (build / beta version) - May indicate a test variant of a feature or a specific software build. This allows Google to attribute data to a specific version of code or an experiment

bl (build label) - Likely refers to an internal build label or version of the Google software module from which the ping originates. It's another parameter used for debugging and performance analysis by Google engineers

et (event type) - signifies the registration of an event, in this case, clicking an address

ct (click type) - provides context about the nature of the event
= slh (search link hit) - a click on a search link
= backbutton - appeared after clicking the browser's "Back" button. This is a very important negative signal for Google. It indicates that the user left the destination page and returned to the SERP, which is significant for measuring pogo-sticking and evaluating satisfaction with the previously clicked result

v (version) - the version number of the telemetry data format

im (interaction mode) - shows how the user is interacting
= M - mouse interaction

pv (Page View) - refers to a value related to the visibility of an element on the search page, measuring, for example, the percentage of visibility. In the CAS (Clicks, Attention, Satisfaction) model, "attention" measurement is described

tni (tab navigation index) - a parameter used in the context of navigation with the Tab key on the client side (CSI / Client Side Instrumentation). It probably tracks the number of tab presses within a given session or page area

m (mode) - an alternative to the im parameter
= M - mouse interaction
= V - keyboard interaction (virtual)
= G - gesture interaction

me (Metrics/Events or Measurement Event) - this is one of the key parameters that contains highly detailed data in a structured string format. It consists of segments such as an event code, timestamp, data type, metrics, and flags. This parameter transmits a set of information regarding performance, response times, and user interactions. It is the most extensive and information-rich parameter, containing encoded data about interactions measured in microseconds, dimensions and positions of elements on the page, time spent viewing them (so-called "attention"), and many other details. It is the core of detailed user behavior tracking
= G - for the mobile version (gesture)
= 74 - for the mobile version, the event code for a "tap"

opi (Operation ID) - an identifier associated with a specific operation, session, or page with which the user initiated a given interaction. If true, this is how Google measures pogo-sticking

ved (visual element data) - its main purpose is to provide Google with detailed information about the link the user clicked, its visual context, and its position in the SERP

vet - similar to the above, this parameter appeared only with AIO, KE, and PAA. Like ved, it is a complex parameter providing extended visual and contextual data about the clicked element. It may contain more detailed information about the element's state, its content, or the data that led to its display. Together with ved, it forms a powerful tool for analyzing visual interactions

fid (feature ID) - This is a unique identifier for a specific Google feature or interface element. In our case, the value 18 is a very likely internal identifier for AI Overviews or their specific interactions. It helps Google track the adoption and usage of individual SERP features

st (session time) - represents the time spent (in milliseconds) on a given element or page before the ping was sent. Another idea is the overall session time. It is definitely an engagement metric

t - Indicates a specific type of trigger or interaction
= fi - probably "first interaction" or "feature interaction"

nt (navigation type?) - This parameter appeared only when expanding AI Overviews. It might signify the type of navigation event as "expand"
= reload - indicates that the page or a specific component on the page (in this case, AI Overviews) was reloaded or re-rendered. In the context of AIO, this could mean that the section was dynamically loaded upon user interaction (in this specific case, expanding the summary). This is undeniable proof that Google monitors not only clicks on links but also dynamic changes within the SERP

fmt (format) - the format in which the data is sent
= jsbp - it seems to be JavaScript Protocol Buffers (aka protobuf, which is found in the Content Warehouse API). A method for serializing structured data created by Google. It takes up less space than JSON / XML

msc (module service context) - a module responsible for capturing the service context (?)
= gwsrpc - very likely means Google Web Search RPC, i.e., communication between different components within the search engine

I've written a comprehensive article that delves into the methodology behind tracking these parameters and discusses their multidimensional role in Google's evaluation and ranking systems. It explores concepts like pogo-sticking (via opi and ct=backbutton) and attention tracking in greater detail

You can find the full analysis here (the article is in Polish): https://seekio.pl/wielowymiarowa-rola-klikniec-w-ocenie-i-rankingu/

Hope this is a valuable contribution. Keep up the fantastic work!

Best regards
Przemek