What does the Q stand for?
Queer.
Questioning, I believe.
Sometimes you'll see LGBTQQ for both.
When there's only one Q, though, it's almost always, in my experience at least, meant to stand for 'Queer'.
In the due course of time and progress, this initialism/acronym will be about twenty characters long.
In some places I've seen LGBTQQIAAP.
What does the second A mean? I can make out the rest.
Allies, i.e. straight people for gay rights (like in the Gay-Straight Alliances).
The LGBT organisation of my area was created under the name "alternative sexualities", which created some ruckus, since some considered it was making heterosexuality superior