Are attachments' requirements (the kind "attach to XXX") play restrictions? The KT_rules only mention paying the gold cost of the attachment as a play restriction, and the FAQ only states that if the attachment's requirement is not met at any moment, the attachment is immediately discarded. But, is possible to attach it at all?
Answer:
A player may only play an attachment if that requirement is met. "Lord only" or "Lady only" are considered to be play restrictions. Specifically in the case of the Dornish Princeling, although due to its text attachments cannot be discarded, a player must first observe any play restrictions.