Purpose
PCB designers rely on fab notes for design control and end product process determination.

Materials
Most common fab note specifications are brand name and / or metal core.

Pantone codes
It's important to align your expectations when choosing pantone codes for LED PCBs. 
Click here for a list of acceptable hues

Your properties
When you specifying by brand name or simply metal core, you are not addressing the most critical features and rnot asserting the most critical features for aluminum / metal core PCB design.

Sample LED PCB Fab Note