Improper use of (P) after rank.

SGM (P) good for him. If you find the profile please congratulate him in his promotion to whatever he thinks he will get promoted. 

(P) has many functions and in the case of warrants, it gets me on the deployment plane sooner because a CW4P is equal to a CW5 which gets on with the O-6 and CSM! There are many other uses for the P such as weight for PCS and housing lists. As for memos, if signing a memo (P) is used if you are in a promotable status. Additionally you can be rated against the next grade for NCOER and OERs.

I'll have to find him again.  I just saw him in the update feed when he was updating his information.  It was a red flag for a faker.

The leader you are is more powerful than the P next to your rank. 

I am not going to lie, it is something of an inside joke between a few of us Lieutenants who are set to promote next week.

For formal correspondence it is completely improper.

Based on AR 25-50 an argument could be made that you are enhancing the image of the Army by including the (P) in Army correspondence. I look at it like a 2LT saluting a 1LT we know its the right thing to do but they (majority) still don't do it. Putting the "P" after rank we know it should not be used (maybe) but they still do it. Actually joking aside I think it comes down to not knowing and now they have the reference they can go and read the chapter on signatures. Good observation. 

I am technically MAJ(P) having made the LTC selection list. But I would never use it. I think it is a tad pretentious, especially for a SPC.

For SSGs, it has its uses i.e. on a Rating Scheme. The minimum AR 623-3 qualification for Senior Rater is SSG(P). Let's everyone know they are allowed to senior rate. For SPC and SGTs, with the new STEP rules, I think it makes great sense, at least in the USAR. Seats for NCOES are hard to come by and there's nothing like a P by your rank to constantly remind leadership they aren't doing enough to get this Soldier to NCOES so he/she can finally get promoted.

They should remove it. We follow rules that are clear in black and white.

The "(P)" is incorrect in your signature. IAW AR 25-50;

(2) Do not use the “(P)” (meaning the signer is promotable) as part of a signature block in Army correspondence unless it benefits or enhances the image of the Army. However, it may be used in an address for such things as congratulatory notes. Examples are—

(a) A lieutenant colonel promotable, filling a colonel position. The position requires the signature of a colonel or higher. This situation would constitute using the (P) in the signature block.

(b) Enhancing or promoting a particular program or issue if it is supported by a potentially higher grade military individual. It may carry more clout if a brigadier general select issues a directive over a colonel.

It isn't a rank, and really shouldn't be used. That is inline with people using "select" in the Air Force.