Some *A partners (depending on check-in site) now print coded *A status on the BP, such as UA*G, TG*G, etc., which is generally enough for partner *A lounge entry. Also, most lounges will provide admission if the carrier prints their own status (but not the *A code) on the BP which correspones to *G. For example, a UA BP might say PREMIER EXEC 100K with no additional notes on *A status. I have found that to be good enough for entry into most *A lounges, at least here in Asia, without the need to drag out a card (which is helpful when your hands are full, dragging a bunch of bags around).

In a worst-case scenario, ask the check-in agent to print up a lounge invitation card, write a note, or call the lounge, which they are generally quite happy to do.