The |timestamp filter adds a timestamp to the URL of a file, i.e. a value that depends on when the file was last modified.
Example:
[(#CHEMIN{squelettes/sakura.jpg})]returns squelettes/sakura.jpg
With the |timestamp filter
[(#CHEMIN{squelettes/sakura.jpg}|timestamp)]returns squelettes/sakura.jpg?1455876748
When changing the file, the timestamp has a new value, and thus forces the user’s browser to re-download the updated file.
See also:
The tag
Filters