I’ve seen, on a few threads, a response to questions on immediate attacks carried out before the combat phase that suggest an enemy is still able to make another attack during the combat phase also, however in the rules reference it says:

6.4a Next enemy attack initiates
The active player (starting with the first player) chooses an eligible enemy that he or she is engaged with to resolve its attack. An eligible enemy is one that has not yet attacked this round and is still able to attack.
Use the “Enemy Attack Resolution” flowchart to resolve an enemy’s attack.

Am I missing something?

Huh. I have no idea why the Rules Reference says that. No, there's nothing you're missing, but a correction needs to be made to the reference. I can only say I'm positive an enemy that makes an immediate attack still attacks the engaged player in the combat phase. I'll send a rules question.

I agree that this must be an RR wording error. Having the OP's proposal be true would be such a sea-change in how numerous scenarios work that I can't imagine it was an intentional revision. Looking forward to seeing the ruling.

It is also this way in the Learn to Play rule book.

I suspect when they were revising the original rules' wording…

Quote

In the combat phase, enemies attack first. All enemies that are engaged with the players attack each round, and the players resolve those attacks one at a time.

…and trying to reconcile this with the FAQ entry on enemies changing engagement…

Quote

Q: When an enemy that has already made an attack engages a new player during the combat phase, does it make another attack?
A: Not unless it is directed to by card effect

…they threw the new verbiage in to try to cover the FAQ ruling within the new rules. And just goofed it a bit, is all.

19 minutes ago, sappidus said:

unless it is directed to by card effect

Cards effects that cause immediate attacks would fall here.

It should probably be read as " An eligible enemy is one that has not yet made its standard attack this round and is still able to attack. "

Official response from the developer:

"Each engaged enemy makes an attack during the combat phase regardless of whether or not it made an attack outside of the combat phase."

Thank you for the clarification.