The following resources are added by the mod, but may be overridden by a resource pack. The Minecraft Wiki has a tutorial on resource pack creation, but the gist is put stuff in a similar directory as the thing you’re overriding.

owo UI

For more info about owo UI’s markup, please see their documentation on the topic.

confirm_release.xml

This is an XML markup file for the confirm release prompt that is shown to the user when a player attempts to release a Pokémon with a release guard on it. It shows a message asking if the player would really like to release this Pokémon, and gives a feedback message as to why they’re being asked.