The case numbers comprise a letter followed by a sequence of numbers:
G
Decisions and opinions of the Enlarged Board of Appeal on referrals
R
Decisions of the Enlarged Board of Appeal on petitions for review
J
Decisions of the Legal Board of Appeal
T
Decisions of a Technical Board of Appeal
D
Decisions of the Disciplinary Board of Appeal
The number before the oblique is a serial number, allocated by chronological order of receipt. The two numbers after the oblique indicate the year of receipt of the appeal.
Source: http://www.epo.org/law-practice/legal-texts/html/caselaw/2019/e/clr_guide_3.htm
Date retrieved: 17 May 2021