Generation 3: Question about two values in Fire Red/ Leaf Green Player's Mailbox

[superzman300]

I'm viewing the player Mailbox Editor for a Fire Red save file. Would someone please clarify what the two values circled in the screenshot below correspond to? No one has been able to answer this question, and I'm curious since I can't find any documentation on it otherwise. They're not TID/ SID- the corresponding Jynx originally holding the mail shows this. At what offset in a Switch save file for Fire Red/ Leaf Green would these two circled variables appear (if different than those on cartridge)? I know it's niche, but I want to understand what PKHex is interpreting here. If they represent sort of "author ID" information, can I use PKhex to view and edit those of the Player directly (e.g., change my own "author ID" info to that of the DONTAE NPC with values 0 and 30863)?

Thank you for your help with this mystery!

[Kaphotics]

Compare it to mail you've written yourself.

Every trainer has to have a TID/SID. The generated mon's TID/SID may be separate from the fake trainer for the mail.

[superzman300]

Thank you very much, that was a wonderful idea! I wrote a random message onto a Pokemon, then moved it to the mailbox. In PKHex, those two fields ended up being the Player's TID and SID, respectively. Given this, the messages from the tradeback NPCs are generated to have different TID/ SID combos than those of the Pokemon the Player received? That's a surprising finding, but then again, there are a lot of unusual quirks in Generation 3 as a whole.

I really appreciate your helpful tip in resolving this mystery, it was driving me a little crazy. Thank you for your time!