NEP-11 improvement WG

[roman-khimov]

This issue links all other issues/comments/PRs related to NEP-11 improvements. If and when we're to decide to update NEP-11 this would be a check list for things to change there.

• NEP-11 properties method inconsistency #141
• Don't check the caller in NEP11 #150
• Multi Token Standard #146 (comment)
• NEP-17/NEP-11 needs update #164
• NEP-11 requires an update for NEP-25 support #206