{{{tiddlyweb.usersign}}} is a member of the environ dictionary that is passed around all the WSGI code in TiddlyWeb. It contains information about the current user, determined by the credentials extractor system. The data is passed to a policy when a policy constraint is checked.

There are two elements in the data structure:

• ''name'': A string representing the identity of the current user. If no user was extracted this will be {{{GUEST}}}. It should never be empty.
• ''roles'': A list of strings of roles. This may be a zero length list.

The name {{{usersign}}} is used because there's nothing preventing the user from having an identifier which bears no resemblance to a name.