How to Exclude Items from Spotlight Search

Exclude anything you don’t want indexed (saves time and annoyance).

See Optimizing Spotlight.

The last thing I want is for Spotlight (“mds”) to interfere with my work by indexing my fast Scratch volume, my Time Machine backup slowed to a crawl, etc. Exclude such things.

Exclude items from being indexed

Exclude backup volumes from Spotlight index;
generally confusing to start editing the wrong document (backup instead of original)