[Zope] (no subject)

[sanket.deshmukh@medienhaus-bremen.de]

hello friends,
can u please tell me where can i find information about the zope converters.
this symbol " : "
here are some example, 

<input type="submit" name="fireEmployees:action" value="Fire!">

 <input type="text" name="people.lname:records"></p> 

i want to know the various possible use of these converters. i couldn't find
detail information in the
zope documentation.
thanks,
Sanket.