37 C.F.R. §2.38
Sec. 5, 60 Stat. 429; 15 U.S.C. 1055
Part 3 pertaining to both patents and trademarks is placed in the grouping pertaining to patents regulations.
Part 4 is placed in the separate grouping of parts pertaining to patents regulations.
Part 5 is placed in the separate grouping of parts pertaining to patents regulations.