When is a capacitor not JUST a capacitor (i.e., not just a filter or part of a resonant circuit)

[Jay Jaeger via cctalk]

(And not acting as part of a resonant circuit)

Answer:  When it is acting like a little delay line.

https://www.computercollection.net/index.php/2020/07/18/q-when-is-a-capacitor-not-just-a-capacitor/