Relief nibs are left-foot oblique (about 15 degrees) stubs.
I do not have a 2442 but my guess is that is a straight stub.
All Durachrome (untipped) and Master Series nibs derived from the earlier dip nibs.
Hoban's book lists among the commercial style gold plated stubs:
- 312 "Judge's": Flexible fine stub (long nib). It evolved to italic Master Series 9312
- 313 "Probate": Flexible medium stub (there is no "descendent" among the renew points)
- 314 "Relief": Flexible medium stub for scial correspondence and manuscript writing. It evolved into the scarse 1314 Durachrome flexible stub, and the 2314-F,M,B and 9314-F,M,B (which are not flexible)
- 239 "Chancellor" Firm small stub - Esterbrook claims that this is the perfect for backhand writing (backhand is when the letters have a left slant). No descendents among the renew points
- 442 "Jackson Stub" Firm medium stub in falcon shape (Esterbrook claimed that it was the most popular stub. Apparently 2442 is the corresponding renew point. Falcon shape refers to this style

AZ