All parameters are optional. Using no parameter equals "{{CUU|dcontribs=check|notified=yes|email=no}}". When the username has contributions, deleted contributions, logs or is less than 6 months old, only one parameter ("contribs=yes", "logs=yes" or "new=yes") is used, the others will be ignored. If you have sent an email to the username, use "email=sent".
Contribs, logs, new, and edited since request will assume "no" unless any value is given.
Dcontribs accepts yes, no, and check, and will assume "check".
Notified will assume "yes" unless "no" is given.
Email accepts yes, no, and sent, and will assume "no".
Interwiki accepts a link to another wiki where the user has edited.
Blockinfo accepts a description of a block currently active on the user.
There is also an optional note parameter, which can be used for other notifications.