This is the system I have developed over the years and that I find perfect for my purposes:

Custom 1: Catalogue (label catalogue number of release)
Custom 2: Release (release date as yyyy-mm-dd for easy sorting, with '00' for unknown days or months)
Custom 3: Source (recorded from where; e.g. CDDA or Vinyl 12")
Custom 4: Keywords (whatever I want... instruments, elements, things it reminds me of, time of day I think it fits best... incl. Magic Node for these)
Custom 5: Origin (country of origin, if one can be clearly determined; e.g. where a band is originally from)

I am so glad to see this topic since I have spent the last three years learning to clean my files a bit and know that there is so much more to do. Now, I will begin to follow y'all how to use the custom fields. Thanks for noting your organization style. Now I just need to learn how to do. Peace out.

Custom1: Source (of the tracks)
Custom2: Country (artist's)
Custom3: Synchro (list of devices & dates the track was synchronized to) [ my own script ]
Custom4: Gapless (yes/no) [ http://www.mediamonkey.com/forum/viewto ... =2&t=42775 ]
Custom5: Playlists (playlists the track belongs to) [ http://www.mediamonkey.com/forum/viewto ... =2&t=39589 ]

:~)

Custom 1 = Purchase status: Amazon, CD, Free download from artist, Last.fm free download (or blank if not obtained in a strictly legal manner )

All others unused

CUSTOM1: Gender
CUSTOM2: Custom Occasion
CUSTOM3: Additional Albums
CUSTOM4: PUID
CUSTOM5: Duplicate Status

Custom4: FreeDB/IMDB ID
Custom5: PUiD

1-3 aren't used, I'm hoping Language get's it's own field now videos have been added.

I'm a curious person. How do you make use of the Custom Fields that MM offers? I use them as:

CUSTOM1: Language
CUSTOM2: Country
CUSTOM3: Topic (what subject is the song about)
CUSTOM4: Fe/Male
CUSTOM5: Instruments

I love these fields as they alleviate the GENRE field. Values like "Spanish", "Portugal", "Politics", "Female fronted metal", "piano pop" are now intercepted. I also use the classifications 'mood' and 'occasion' to intercept values like "sex" "fun", "party", "morose", et cetera. And I use GenreFinder to fill these values automatically. Sounds cool huh

If, how do you use these custom fields?