This is mainly of interest to addon authors.

The member=, guild=, and realm= params are no longer used. Instead, a single a= param (a stands for anchor) has been added with almost the same syntax.

The following substitutions should cause identical behavior:

member=foo to a=c:foo
guild=bar to a=g:bar
realm=baz to a=r:baz

The c:/g:/r: prefix may be omitted, but the results are less predictable and the format is mainly intended for human entry.

The purpose of this change is being able to maintain a selected guild/character when pages are visited on a wider scope. This means the following also works:

p=realm-memberslist&a=c:Azymyrta@EU-Aggramar

Finally, two properties have been added to the $roster object.
atype: The type of anchor (char, guild, or realm)
anchor: The contents of the anchor, not including the c:/g:/r: prefix