How do LFN's work?

A. Long File Names are stored using a series of linked directory entries. A LFN will use one directory entry for its alias (the alias is the 8.3 name automatically generated), and a hidden secondary directory entry for every 13 characters in its name, so if you had a 200 character long file name, this would use 17 entries!

The alias is generated using the first six characters of the LFN, then a ~ and a number for the first 4 versions of a files with the same first six characters, e.g. for the file
john savills file.txt
the names generated would be johnsa~1.txt, johnsa~2 etc.

After the first 4 version of a file, only the first two characters of the file name are used, and the last 6 are generated, e.g. jo0E38~1.txt