A couple of examples:
50mm f1.4 Zuiko AUTO-S
Introduced as part of the original "M" system. Early examples are labeled as G.Zuiko and have silver colored accents around the filter mounting threads as well as the aperture ring: OLYMPUS OM-SYSTEM G.ZUIKO AUTO-S 1:1.4 f=50mm 470854. There was also a version of the G.Zuiko without the silver markings. When Olympus started to multi-coat all lenses, the 'G' was dropped and the lenses were labeled "MC". The last version was simply labeled as follows: OLYMPUS OM-SYSTEM ZUIKO AUTO-S 50mm 1:1.4 1123989 Japan. I used my serial number as an example and this is definitely a multi-coated lens.
35mm f2.0 Zuiko AUTO-W
I have one with a low serial number that is a "Silver-nose". The complete labeling on the filter ring is: OLYMPUS OM-SYSTEM ZUIKO MC AUTO-W 1:2 f=35mm 106322 Japan.
I have a version that was made a little later and does not have the silver accents that is labeled: OLYMPUS OM-SYSTEM ZUIKO MC AUTO-W 1:2 f=35mm 129334 Japan.
The final version from after 1981 is labeled as follows: OLYMPUS OM-SYSTEM ZUIKO AUTO-W 35mm 1:2 1508xx made in Japan.
Does it change too much that they're simply just single-coated lenses or however this feature is not so negative after all?
The 2 versions of the 50 1.4 that are MC have elements with green/purple reflections. Type 5 has these reflections but does NOT have MC on the name ring. Type 4 (below serial number 1,110,000) has same reflections and DOES have MC on the name ring. Type 3-2-1 are single coated and have G Zuiko (meaning 7 elements, G being the 7th letter of the alphabet) on the name ring. SC coating may have a yellowish look. Last multicoated version with a shade will outperform any SC with a lens shade. John