BNETDocs
C>S 0x27 SID_WRITEUSERDATA
Message Id:0x27
Message Name:SID_WRITEUSERDATA
Direction:Client to Server
Used By:Starcraft Original, Starcraft Broodwar
Starcraft Shareware, Starcraft Japanese
Diablo Retail, Diablo Shareware
Diablo II, Diablo II Lord of Destruction
Warcraft II BNE, Warcraft III Reign of Chaos
Warcraft III The Frozen Throne
Format:

(UINT32) Number of accounts
(UINT32) Number of keys
(STRING) [] Accounts to update
(STRING) [] Keys to update
(STRING) [] New values

Remarks

Updates the Client's profile. Currently, the allowed keys for this are Profile\Sex, Profile\Location, and Profile\Description. The maximum length for the values is 512, including the null terminator.

See SID_READUSERDATA for more information.

| Edited:
Comments
Davnit

As of Starcraft version 1.15 (many many years prior to me making this comment), Blizzard removed the Sex field from user profiles and attempting to write this key will result in an IP ban.

Edit: this is based off a code comment found in StealthBot, but has not been confirmed.