Audio Toolkit

3 March 2026 | 6 min read

How to read the UCS category list without losing an afternoon

Category, subcategory, CatID, synonyms. Four columns, one spreadsheet, and a lot of people who give up on the second scroll.

Open the UCS spreadsheet for the first time and it feels like a tax form. It is actually a simple two level hierarchy with a code column and a synonym column bolted on to help you search.

Category and subcategory

The top level Category is broad: DOORS, WEATHER, VEHICLES, FOLEY. The Subcategory narrows it: Wood, Rain, Car Sports, Cloth. The CatID is simply the two joined into a compact code, which is what actually goes into your filename.

  • Category DOORS plus subcategory Wood gives CatID DOORWood.
  • Category WEATHER plus subcategory Rain gives CatID WEATRain.
  • Category FOLEY plus subcategory Cloth gives CatID FOLYCloth.

The synonyms column is the real search tool

Most people fail at UCS because they look for the word they have in their head. The synonym column exists for exactly that. Searching squeak lands you on the right door or hinge category even though squeak is not a category name.

Pick the sound, not the source

The classic mistake is categorising by what made the noise on set rather than by what it will be used as. A watermelon dropped on concrete for a gore effect belongs in the body impact family, not in FOOD. Your future self is searching for the use, not the trick.

When nothing fits

There is a general or miscellaneous subcategory in most families. Use it sparingly. A library where ten percent of files sit in misc is a library with a ten percent search failure rate. If you keep needing a category that does not exist, the UCS list is community maintained and accepts proposals.

Keep the code and the metadata in sync

Whatever CatID you choose, write the same words into the file description field. Databases index metadata, operating systems index filenames, and you want both to agree.

Frequently asked questions

How many UCS categories are there?
Several hundred CatIDs across around eighty top level categories, and the list grows with community proposals.
Can I invent my own CatID?
You can, but it breaks the point of a shared standard. Propose it to the UCS maintainers instead, and use the closest existing code in the meantime.
Does the CatID need to be capitalised exactly?
Yes, keep the published casing. Some databases match case sensitively and inconsistent casing splits your search results.

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