abbreviationsword-meaning
In a joke image (second image from top), there's mentioning of preparing for RA inspection.
Googling leads to medical material on rheumatism and disambiguitization produces way too many different results.
What could RA mean in the context of inspecting a room, flat or, possibly, bathroom?
They don't, because the word used is "senior", not "elder". ("Senior" is abbreviated "Sr.")
When referring to relatives, "elder" is most often used for siblings. In this context, its opposite is "younger". Since these are comparative terms rather than labels, there is not generally a need to abbreviate them.
Skill, as you mentioned is too short to be abbreviated and no abbreviations will make sense for the word. However, I've seen in many places, where an image that represents skills is used to convey the same meaning.
Best Answer
I think that stands for Resident Assistant.
From Wikipedia: