Requested feature overview description.
Modify the Parent Post ID field to accept input in the form https://e621.net/post/show/#######/ by stripping out everything before and after the ID (#######).

Why would it be useful?
I assume the most common way to add the parent to a post is by copying the parent ID from the URL and pasting it into the field. This saves a step and I think it would be easy to implement.

receive input
delete any instances of "e621.net"
delete any text prior to first numeric character
delete any text after first numeric string

This would also make the field more robust against easy typos like "v#######" (from pasting).

What part(s) of the site page(s) are affected?
Posts

+1. Saves time and helps prevent bad inputs.

+1

I would appreciate this.