I remember having a similar issue in 2000, before any (meaningful) client-side javascript. Solution: each link that did something also had a request_id paramete

I remember having a similar issue in 2000, before any (meaningful) client-side javascript. Solution: each link that did something also had a request_id parameter, which was a timestamp in milliseconds. Two requests with the same request_id meant the user had clicked something twice, so any action would NOT be performed multiple times if the same request_id came in more than once. This let users double click on links and have the action performed only once. In 2000, hyperlinks were still confusing to some users who were used to "double-click = open", especially for file icons. EDIT: added text in italics because initial wording was confusing.