This field is for the date of the last release of this wiki sofware.
Please use the ISO 8601 following pattern : “YYYY-MM-DD”.
(for some of the wikis this field has been filled in with a version number. To be fixed?)
A very old Last release date might indicate that the project has gone stagnant, with no new effort being put into development. Some developers are not facing up to the recent challenge of wiki spam very well for example. It's a good idea to check the wiki homepage to get a feel for how actively the wiki is being developed.