Figures of Merit (Erdős number) in Resume/CV I've noticed recently that colleagues, friends, and others seeking employment, have shown, among other things, their Erdős number on their resume/CV.  I've also seen some put down their h-index, or their publication with the most citations (the running tally of citations for that publication), or the Impact Factor journal that they have ever published in, etc.

I know there is a question on just h-index in a CV/resume (so please do not mark as duplicate), but this is a broader question about other figures of merit, especially Erdős number.

I realize that having a CV/resume that stands out is important and can give an edge to getting that coveted position, but is listing these types of things appropriate?

Let me just make clear that I am not endorsing doing this or saying that I have done it, I am just asking if this is common, acceptable, or purposeful.
As a mathematician, I don't view an Erdős number as a sign of merit in any serious way. It's more of a cultural in-joke.  

There are over 9,000 people with Erdős number 2, and far more than that with Erdős number 3, so it doesn't really set you apart. So, if you published with Erdős, that fact will be clear form your list of papers, and if you haven't, your Erdős number tells very little about you. 

My own Erdős number is 3 (two ways), FWIW.