Re-doing this for the 6.2x UBB, things have changed
If you are working on a modification that requires profile fields, please request one here so there aren't conflicts between modifications. Requests begin at #51
Base Code Profile Fields (6.2.1):0 - user name
1 - password
2 - email address
3 - homepage
4 - permissions (Write&)
5 - occupation
6 - location
7 - post count
8 - status (Admin|Mod|Member)
9 - interests
10 - register date (YYYY-MM-DD)
11 - email address viewable (yes|no)
12 - signature
13 - ICQ
14 - allow mass email (yes|no)
15 - publically displayed name
16 - custom field 1
17 - custom field 2
18 - custom field 3
19 - custom field 4
20 - member picture
21 - default topics viewed
22 - AIM
23 - publically displayed name of last user to update this profile|^|member number of last user to update this profile|^|update date
24 - profile locked (yes|no)
25 - publically display user rating (yes|no)
26 - approved registration/moderation que (yes|no)
27 - PMs enabled (yes|no)
28 - PM notify enabled (yes|no)
29 - PMs locked (yes|no)("no" means locked)
30 - Last Post Info (forum|thread|post|YYYY-MM-DD|IP)
31 - custom title
32 - birthdate|yes/no
33 - last profile edit/registration IP
34 - hide from wol (0|1)
35 - ban user from polling (0|1)
New For 6.336 - Ban user from polling (1 = yes)
37 - Relative or abs URL to user Avatar
38 - Lock user avatar (1 = yes) | No user avatar (1 = yes) | User hides other avatars (1 = yes)
Reserved Profile Fields for Modification:55 - MyStyle (chosen template)
56 - DT's Extra (custom display category)
57 - DT's Extra (custom display item)
59-74 - eXtremeTim's 16 extra custom fields