I am getting a little confused here. First of all, I assumed that by selecting the main menu option 'Edit/Update tags when file info changes' that would be enough to ensure all metadata changes would be automatically written back to the tags stored in my FLAC files. Then MrC told me that I had to select the 'Save in file tags (when possible)' option in the setup of my new Sub-Genre custom tag. Both of these have been done, and now you are saying that I also need to select something called 'Update tags from library'.
Three configuration settings for the same thing seems a little excessive! More to the point, where do I find this option called 'Update tags from library'? I could find no reference to it via a search of the MC18 Help pages.
I had already tried and failed to find my Sub_genre tag via the Extended fields list within MP3Tag, which I why I am assuming this tag has not yet been written to the FLAC file by MC18. I have no idea what an 'embedded cue sheet' might be, so I'm guessing that this is probably not relevant in my case.
David
Update tags when file info changes applies to all fields in the library. Disabling it prevents any changes to tags to be written to your files. It is a global option.
The option to save a custom field to a file is an option that only applies to that field. This option is there so people can create a database field visible in the library but is not stored in file tags to maintain compatibility, for instance with other programs.
MrC explained the update tags from library, it is simply an option to force MC to write out all the library fields back to the files. To give you a practical example when you would need this, I access my files from 2 different pc's. Music resides on a network share and on one pc I added a field and enabled to write the tag to files. This worked fine, and I added the field to the 2nd pc, but forgot to enable to write it to files. I did an 'update library from tags', which filled the field just fine but when I changed this field from pc2, pc1 did not pick up the changes when I did an 'update library from tags'. After I enabled the option to write that field to files on pc2, I had to do an 'update tags from library' to write the values to files, and then I could do an 'update library from tags' on pc1.
These options are available under right mouse click on a track (or selection of tracks), choose Library.