Sometimes a volume which was indexed within a project is later not available, e.g. a CD, USB-Stick or network drive. The menu entry "Include unavailable files" tells FindWord how to handle this:
If the word "interpretieren" is highlighted then 6 files are listed, and the project contains 8.729 different words from a total of 54.748 words.
A double click, for example, on the file "neuer Tarif.pdf", which is located on the CD, leads to a message that the file is not available.
Now selecting "interpretieren" leads to only one file with a hit - and the project contains only 2608 different words from a total of 19452.