Relevant tag information
mac:
Hardware related questions of computers sold/made by Apple. Use [osx] for the operating system, and use [mac-address] for MAC addresses instead.
osx:
A Unix-based operating system developed and sold by Apple Inc. For Mac hardware questions, use [mac].
All of the threads I could find on meta are from at least 4 years ago. Since mac is for hardware and osx is for the operating system, it's unclear to me (upon reading the tag excerpts from a new user perspective) how one would tag a question about software on a mac.
E.G. microsoft-excel-2011,microsoft-excel-2008 and microsoft-excel-2002 all read
[...] Microsoft's spreadsheet application for Mac.
Since microsoft-excel-2016 is cross-platform, it stands to reason that if you're using a mac, you need to add the tag osx rather than mac, despite the trend from how the other excel tags are worded using mac.
Reading that osx is for the operating system might lead a user to think it's not the right tag.
Suggestion
Include in the osx excerpt language that it applies to software running on the operating system, not just the operating system itself.