The IDENTIFIERS feature tries to assign station labels to "peaking carriers" found in the spectrum on the HOME display. A "peaking carrier" is a carrier which has the strongest signal power at any time within the file - the CATWALK spectrum style is handy for spotting these, because if the carrier ever rises "topmost", it can be seen with white color on the spectrum and thus used for searching the IDENTIFIER (gray carriers are ignored). IDENTIFIERS uses various information (not only the listed offsets) in this task. Station labels listed with the white color have the best probability to be correct, other "good candidates" are listed as gray.
IDENTIFIERS can be enabled by defining SETTINGS > GRAPHICS > IDENTIFIERS > YES. In addition, in order to see the IDENTIFIERS, the mouse cursor must be moved to the SPECTOR peak frequency label: the label turns red showing the "best bet" for this peak and other candidates are shown on the HOME spectrum.
If you are maintaining the private OFFSET list, you can update your local OFFSETS.txt file by clicking that red label (see MY_OFFSETS for details).