As far as I know a recognition slip isn't quite the same as an assessment, however I believe they still go on your file in the office and I'm sure they can't do anything other than help your chances of getting a contract!!
They used to be used quite a bit but been forgotten about recently what with the drive on everyone having assessments! I think it's quite nice though to get a little thanks in that way from other crew and it's a more official way of doing it, so your csbm gets to see it!
I think any of the other crew can give you one, for any reason they think worth it, and vice versa, IFS or CC!