If you have an old copy of Issue 4 or Issue 3, you are likely out of compliance. Issue 5, published by Telcordia, introduced several significant updates that reflect modern network architectures—specifically the rise of Edge Computing, 5G small cells, and high-density server racks.
To understand what you are looking for in the PDF, here are the four main "Tests" you will need to design for: gr-63-core issue 5 pdf
Defines dimensions and floor loading limits. If you have an old copy of Issue
Limits dust, corrosive gases, and defines fan filter requirements. Purchasing and Official Sources GR 63 CORE : ISSUE 5 NEBS REQUIREMENTS - Intertek Inform published by Telcordia
The standard remains the "backbone" of NEBS, addressing these fundamental physical criteria: