It seems to be referring to IFR currency requirements.
If you are not instrument rated, don't worry about it. If you are, you should know what it means
I am IFR rated, and current. And I even asked a local CFII.
Note: There are separate entries for Approaches and Holds; which is what I track.
Tim
14 CFR 61.57 (C)And what do you need to prove instrument currency?