The first step in matching the sighting of a whale is to determine all of the useful information that is available in the images. This includes: Feature Identification Codes, including One-side head codes, Full Composite Codes (which are only used when they supply relational information not captured by one-side head codes), number of post-blowhole callosities, belly and chin color, the sex if visible from photographs, and any other matching features.
For example, the images below show a whale that has a full composite code of C11 (4 asymmetrical peninsulas), a right head code of C2 (2 peninsulas that side), and a left head code of C2 (2 peninsulas that side). In addition, you can see that there are medium lips on the right and the left (though the left lip could also be coded as small), 2 post- blowhole callosities, no white blowholes, and a distinctive mark on the back.
NOAA Fisheries Service/Permit No. 775-1600