My ack conf file

.ackrc

# General Ack Settings
####################################################################

# only search with case sensitivity if there is mixed case
--smart-case
# follow symlinks
--follow


# Ack Type Settings
####################################################################

--type-set=tpl=.tpl

# add some more zope files to the plone type
--type-add=plone=.zcml,.props,.dtml,.vpy,.kss
--type-add=python=.cpy,.vpy
# add specific type for page templates
--type-set=zpt=.pt,.cpt
# add .cfg for buildout files
--type-set=buildout=.cfg
# add a specific type for ZCML files
--type-set=zcml=.zcml
# add markdown, textile, and reStructuredText
--type-set=plaintext=.md,.mdown,.markdown,.mkdn,.textile,.rst,.txt
# plain text CSV files
--type-set=csv=.txt,.csv,.tsv
# add in a type for gettext messages
--type-set=gettext=.pot,.po

# types to ignore by default
--nogettext