I forgot, do I need to register it in the INI?

Yes, as the first bsa in the list.

Why? Are you using Wrye Bash or OBMM?

Speaking of which, what is the purpose of ArchiveInvalidationInvalidated!.bsa? ...

It is a redirection BSA, and the reason why I asked my questions earlier is because both OBMM and Wrye Bash offer BSA redirection features and automatically register the BSA. If you are using either of those utilities, installing ArchiveInvalidation Invalidated! is a waste...

BSAs and Archive Invalidation - http://tesivpositive.animolious.com/?page=bsas_and_archive_invalidation

Start OBMM.
Click Utilities.
Select Archive invalidation. You'll get a popup window.
Click BSA redirection (it's the default choice).
Click Update Now.
Close the Archive invalidation popup (click the red X in the upper-left corner).
Quit OBMM or click Launch Oblivion.

Oh, ok, but if I'm not worg, ArchiveInvalidationInvalidated!.bsa in installed by WryBash itself... OBMM installs obmm\BSAInvalidation.bsa. So what's the meaning? A waste?

I'm using Wrye Bash. Would the redirection feature work exactly like the ArchiveInvalidationInvalidated!.bsa?

This point is the motivation for my first question: "Why?" If that is Bash's BSA, then Bash will take care of the registration. Leave it alone. However, ArchiveInvalidation Invalidated! uses the same name for its BSA, if I recall correctly, so I do not really know the circumstances of that BSA at this point.


Edit: If that is Bash's BSA, BSA Redirection must already be checked. If you right-click on Packages in the Installers tab, that option should have a check mark next to it. Otherwise, I do not know why Bash would've dropped that BSA in the Data folder...

EDIT: Enabling "BSA Redirection" registers ArchiveInvalidationInvalidated!.bsa automatically.

Uhmm.. this is a strange topic... sinse I checked BSA Redirection but I don't find any ArciveInvaldationIvalidaded.bsa whathoever...

Just register ArchiveInvalidationInvalidated! in the .ini. This is the most efficient method of archive invalidation. If you use OBMM you have to update it every time you add new texture replacers.

OBMM automatically re-registers it, and the same goes for BAIN. At least, OBMM has an auto-update on exit function, but the automatic re-registration is default. I did not mess with that option at all. I thought it gave a warning about that check being unnecessary when you choose it... OBMM's BSA is named differently too. Isn't it more efficient for the tool to handle the registration automatically?

That was for BSA alteration, BSA redirection is a "set it and forget it" method...unless you regenerate your .ini from scratch, in which case you need to re-register.