Yes, it is and, if the US Army wants to recall my 69-year old self back into active service, I will come back in as required. In fact, I dare them to do so ... because if they recall me for even one day, when they discharge me again, my new retirement pay will be based on the pay chart I was recalled under. And THAT would be a substantial raise.
Not that I really expect them to do so, but, hey, they've screwed everything else up ...
Ha—one can hope!