Is "the be verb" skipped before "allowed" (like "Carry-on is allowed.")? Is it common to skip like this? Or is "allow" just past tense?
There is no verb before "allowed" here because the speaker is speaking in a direct way, similar to how a sign would be written, because he is stating a rule. "Skipping" a verb like this is not common in general, but when stating a rule, omitting a verb like this is common.