Museum standards for design. What are they?

[NATA NOVA]

I have often encountered this phrase in describing the requirements for work submitted for exhibition (competitions, etc.) ..
I wanted to learn the current trends and practices the principles of relevant experience .
For example:
Antirefleksnoe glass with him do not accept. (I wonder why ?)
Stale (old) passport - it's understandable ..
Plastic frames do not accept because it is difficult to screw the gallery employees holders;
And anyway, who thinks about , " museum standards of design "? (refers to traditional materials and techniques)