CiviCRM Community Forums (archive)

I want to start extending the fields included in CiviCRM in two ways - increasing the number of fields in the existing civicrm profiles and creating my own fieldsets of data that show up in a contact's record.  The custom fieldsets of data seems fairly straightforward, but I'm confused about the existing fields.

In the profile, you can go to add a field and select the type of record, like contact or individual, and you get a different dropdown of fields to choose from that you can add into the profile.  I can't seem to find the location of these fields anywhere in the administration, however. 

I checked out the ebook and googled around for it, but I can't seem to find where these fields are... am I blind or are they buried somewhere, or are the core fields not available to modify?