The mechanical drawing below contains two dimensions (2-Ø2.30 and 4-Ø0.92) that I can't make heads or tails of. I have spent quite a while researching mechanical dimensional and tolerance conventions again, since I could not remember what this format meant. I was not able to find this particular format after looking through just over ten web pages with varying search terms.
My educated guess would be that the prefix (4- / 2-) is some special format of a tolerance value. Since the drawing is in millimeters and the hole diameters are quite small, I don't assume these prefixes to be in millimeters. From what I can tell, the suggested diameters are 2.3mm and 0.92mm, but I stand to be corrected.
I would appreciate any feedback on what these values exactly refer to.