If’ve found in chapter 9 of the manual following excerpt:
“… A kit is a collection of eight Sounds. A Sound is a sample, plus all the settings in the PARAMETER pages (SRC, FLTR, AMP, and LFO). A Sound can be assigned to one of the eight audio tracks.
Each of the audio tracks can contain one Sound. A Sound that has been imported from the +Drive to a pattern becomes part of the active pattern. Any changes made to a Sound will therefore not affect the stored Sound or kit. It will only affect the Sound in the active pattern. You can export (and in that way save) a
Sound from the active pattern to the +Drive. For more information, please see “9.3 SOUND MANAGER” on page 24.
A sample that is used in a Sound or a pattern can be renamed or moved and still work as intended. This is due to a hash function that adds a file specific value to every file, and this value is independent of the file name or the file’s location in the data structure. However, if you delete a sample, it will not be included in any Sounds or patterns anymore.
• When a Sound is imported to a pattern, it becomes a copy of the Sound on the +Drive and is not linked to the original Sound stored on the +Drive. Instead, it fully becomes a part of the pattern.
• If you delete a sample from the +Drive, it will not be included in any Sounds or patterns anymore. …”
So “hash function” is the secret sauce.
Edit: Replaced hashtag by hash.