Read by the validators and services, which refuse what breaks a limit, and by the forms, which say so before sending. Lengths are JavaScript string lengths, so an emoji may count for two. The category limits are checked on the server only.
USERNAME_MIN: number
USERNAME_MAX: number
PASSWORD_MIN: number
PASSWORD_MAX: number
DUMP_TITLE_MAX: number
DUMP_COMMENT_MAX: number
Applies to a dump's note, which the API calls its comment.
PLAYLIST_TITLE_MAX: number
PLAYLIST_DESCRIPTION_MAX: number
COMMENT_BODY_MAX: number
USER_DESCRIPTION_MAX: number
CATEGORY_NAME_MAX: number
CATEGORY_SLUG_MAX: number
CHAT_MESSAGE_MAX: number