The standard Drupal 8 block visibility page settings allow you to either include the listed paths (via "Show for all listed pages" or exclude the listed paths (via "Hide for all listed pages") - but you can never include and exclude at the same time. The Block Exclude Pages module provides a solution to this.
Consider the following situation: you have a block that needs to appear at all pages whose URL begins with "/about", with the exception of "/about/me". With just Drupal 8 core visibility rules, it isn't possible to easily make this happen.
With the Block Exclude Pages module installed and enabled, the following visibility rules can then be used:
(Show for all listed pages" selected.)
The Block Exclude Pages module allows you to use the "!" character as a negation - problem solved!
I think 🤔 it should be
You are correct - thank you!