Usage

To install User:MC10/rollbackSummary.js, add the following to Special:MyPage/skin.js or Special:MyPage/common.js:

// [[User:MC10/rollbackSummary.js]]
importScript('User:MC10/rollbackSummary.js');

On diff pages, history pages, user contribution pages, recent changes, and personal watchlists, a "sum" link will appear next to the "rollback" link. When you click on "sum", you will be prompted to enter a summary. Press Cancel to cancel, or leave a blank summary to use the default. In the summary, the text "$user" will automatically be replaced with the user name you're reverting. e.g., "rv edits by $user; not true". Then press OK to submit.

Extra options

To disable the link from appearing on any one of the pages, add a line containing a list after the "importScript" statement. The options are 'diff', 'history', 'user', 'recent', and 'watchlist'. For example, to disable the link on history pages and user contribution pages:

var rollbackLinksDisable = [ "history", "user" ]

In addition, there is an option to have some default text in the summary pop-up instead of a blank text field. For example:

var rollbackSummaryDefault = "[[WP:RBK|Reverted]] edits by [[Special:Contributions/$2|$2]] ([[User talk:$2|talk]]) to last version by $1"
Finally

None of the above affects how rollback is done if you use the 'rollback' link instead of the 'sum' link. Please contact me if there are any problems.