@Utsav Shah, I am not sure what documentation might exist, the general principle was that

uuid

's generated by the system will start with a known set of characters, eg.

FFFFEEE

For example on my test device:

osquery> SELECT SUBSTR(uuid,1,16), COUNT(SUBSTR(uuid,1,16)) FROM users GROUP BY SUBSTR(uuid,1,16);
+-------------------+--------------------------+
| SUBSTR(uuid,1,16) | COUNT(SUBSTR(uuid,1,16)) |
+-------------------+--------------------------+
| 425D5A4B-8EF2-4E  | 1                        |
| 595A9274-B7F3-43  | 1                        |
| 76057753-404D-41  | 1                        |
| E96D1341-6627-4E  | 1                        |
| FFFFEEEE-DDDD-CC  | 112                      |
+-------------------+--------------------------+

oh interesting. thanks a lot!