Last modified: 2014-06-07 22:16:47 UTC
Currently, {{REVISIONTIMESTAMP}} returns the current timestamp (i.e., the same as {{CURRENTTIMESTAMP}}) while {{REVISIONTIMESTAMP: {{FULLPAGENAME}} }} returns the timestamp of the last edit of the page being edited. See: https://en.wikipedia.org/wiki/Wikipedia:Sandbox?oldid=595173679&action=edit&preview=yes
This was intent, see Gerrit change #76534: "When the given param is equal to the current title of the parser, the parser function will yield the previous versions on preview and on substitution, that includes empty strings when used on page creation, but using the values from the current version for page view, including viewing old revisions." Supporting WONTFIX
Whether originally intentional or not, there's no reason {{REVISIONTIMESTAMP}} and {{REVISIONTIMESTAMP:{{FULLPAGENAME}}}} (or the others) should ever differ.
