Classic Protocol Extension/Proposals

Feel free to post your extension proposals here. Please use existing extensions as your guide to formatting. Please sign your proposal by ending it with ~~~~. Write your comments

Template

===ExtensionName===
:Brief summary of the extension.
:'''Motivation''': Explain why this is needed or how it is useful.
:'''Client Behavior''': Detailed description of all new behavior that game clients need to implement in order to support this extension. Consider interaction with other extensions.
:'''Server Behavior''': Detailed description of all new behavior that game servers need to implement in order to support this extension. Consider interaction with other extensions.
:(packet definitions go here)
:(remarks and comments go here)
:Proposed by ~~~~