Which group PTFs do we need?

How does one tell whether they need a certain PTF group?  "Work with PTF
Groups" on our v5r2 box shows 4 groups:
  SF99519
  SF99502
  SF99169
  SF99098

However, when I go to the PSP site for group PTFs, there are 19 groups!  I
looked at some of the detail and can't find useful references to LPP id's
that would tell you whether you need it or not.  I looked at the "SF99085:
520 520 Backup Recovery Solutions" and can't tell if this is strictly for
BRMS shops or what.  A snip from the group site:

  Description:  BRMS, TA, LD, SR and now LPAR Group PTF
  Product: 5722SS1, 572299, 57222BR1

(BTW, that is "sic"; I copy/pasted the above; see the Product:)

We do not have BRMS, however what is "TA, LD, SR"?  Is SR = "Save/Restore"?
If so, then that would be everybody, right?

And SF99085 might be an easy one if every shop needs it.  What product would
I need to look for to see if I should install group SF99246 (520 WebSphere
App Server ND V5.0)?  The detail on that doesn't even show a product ID.

Advice and RTFM links appreciated!

db