[wp-xmlrpc] Protected metadata impact on 3rd party plugins and API

[Daniel Jalkut]

Hi everybody. A change that went in to 3.1.3 is having an effect on the API and how some of my customers use it to edit custom field values for e.g. the All In One SEO pack.

http://core.trac.wordpress.org/changeset/17994

This change altered the behavior of WordPress so that custom fields with a leading _ underscore cannot be edited by clients of the API. It seems that AIO SEO uses (or used? don't know if they've updated the plugin) custom field names like "_aioseop_title" and "_aioseop_keywords". Presumably this is because they don't want to have the custom fields show up in the standard custom field editing UI in WordPress.

The net effect is some customers can no longer edit the pertinent custom field values for 3rd party plugins they have installed. 

Does anybody know if the WordPress team stance on this is that 3rd party plugins should only use "non-protected" naming conventions for their custom field keys?

If it is expected to be acceptable for 3rd party developers to continue using these "protected" custom field values, then I think the team should consider revising the changes in r17994 so that protected custom fields are still editable via the API.

Daniel