New Lens: Sigma 150-500mm f/5-6.3 APO DG OS HSM on Canon
I found exiv2 was not recognising this lens: http://www.sigma-imaging-uk.com/lens/telephoto-lens/apo-150-500mm-f5-6-3-dg-os-hsm when attached to my Canon but was instead reporting the numeric ID. From an example in one of the forums I have changed the canonmn.ccp file to correctly recognise it and attach the patch. I have not included an example photo with the EXIF data as they are big but if you want one as a test case then I can provide one.
Updated by Steve Fosdick about 7 years ago
To add to my previous comments I took the description from the Sigma website as linked in my previous comments but edited slightly to bring it in line with appears to be the standard form which should therefore suit to code used to distinguish lenses with the same ID number. I have tested this with one of my photos and exiv2 now reports the correct lens. I don't have any other of the lenses that show up as ID 174 to test for false positives.