What to do with map to file

We are implementing LOINC code in our application. Can someone tell me what to do with the map to table? Is this table to find a LOINC code wich is not in the LOINC table?

I checked all the loinc numbers in the map_to file. There 2810 records. If I check the all the values in the first column LOINC against the LOINC table I get a match of 2355. If I match the second column MAP_to against the LOINC table I get 2377 matches. I expect a full match on the second colum. Is there someone who can explain why there is not a full match or what is the use of this file?

The MAP_TO table is used to identify the appropriate replacement for LOINC terms that have been DEPRECATED or DISCOURAGED. You can find a detailed explanation in section 11.2 of the LOINC Users’ Guide.

I have examined the MAP_TO table distributed in the 2.59 release of LOINC. I can find no LOINC number in the MAP_TO.LOINC or MAP_TO.MAP_TO column that does not also appear in the LOINC.LOINC column. Can you please provide examples of the LOINC numbers that you cannot find?