My team has read over this rule many times. If you have ever bought the pneumatics air tank or pistons, you know the cheap plastic wrap covering it. My team has bought 4 pneumatics kits, and we have removed the cheap plastic wrap from all of the pistons and air tanks. Does this mean that if we were to use these pistons and air tanks it would be considered illegal? If it is, many teams have done this because let’s be honest… it looks hideous, especially for bots that have a color scheme. If Vex changed R23a, they should add another pass with this as well. Anyways, my question remains the same: Is this legal?
I believe your only problem will be extra scrutiny during inspection. A similar question to your was answered in Q&A: Question 3136.
Check the Q&A yourself, always important to verify but this is what I found regarding R28
"Normal wear and tear that damages factory-applied labels does not inherently make an otherwise legal pneumatic component immediately illegal.
Inspectors may use other identifiable characteristics of the part, such as its dimensions, construction, fittings, color, shape, or other distinctive features, to determine whether it is a legal VEX component. Comparing the part to a known-legal component with intact factory labels may help facilitate this process.
The easiest way to ensure inspection of these parts proceeds smoothly is to ensure that factory labels remain clearly visible to Robot inspectors whenever possible.
Teams should expect additional scrutiny if a part cannot be readily identified during inspection, and should understand that inspectors may deem a part illegal if they cannot reasonably verify that it is a legal VEX component."