[Openid-specs-mobile-profile] Issue #121: CIBA: binding_message restrictions (openid/mobile)

[Takahiko Kawasaki]

New issue 121: CIBA: binding_message restrictions
https://bitbucket.org/openid/mobile/issues/121/ciba-binding_message-restrictions

Takahiko Kawasaki:

It will help implementers if the description of the `binding_message` request parameter also includes detailed explicit restrictions on its length and valid characters as that of the `client_notification_token` request parameter does.