USEF horse registration for USDF lifetime recorded horses

Can someone point me to the page on the USEF site, or in the rules, that specify that a horse with lifetime USDF registration does not need to have a USEF registration number? (IOW, USEF will accept the USDF number.)

I saw it the other day and should have bookmarked it, but now cannot find it.

GR1101.1

on my phone, can’t cut/paste well.

Unless you want to qualify for and ride in your Regional Championships. Then the horse must have a USEF (Annual or Lifetime) Membership recorded at the time qualifying scores are earned and at the time of the championships.