Multiple units of a singular shelf... If I refer to the group of units, should I use "shelfs" or "shelves" [closed]

I have multiple packages with a single shelf inside.

If I refer to the multiple packages using some form or variation of "shelf" instead of "packages", should I use "shelfs" or "shelves?"

My inclination is to use "shelfs", since I'm referring to multiple singular units, rather than the all the shelves together as a group entity. Or am I completely off-base here?

Is there a specific name for this non-standard convention, if it exists? (Bonus brownie points if someone can answer if this convention exists in non-English languages.)

Solution 1:

In English, the only plural of "shelf" is "shelves". I guess that if you use "shelfs" (without some explanation), your readers will just assume that English is not your native language, so you did not know any better.