Just a thought...
There in
mtab labels of sda5 + sda6 combined give the label under question "FILE RECOVERY".
There is a backslash
\ in those lines that Linux
doesn't use in its file structure.

You are right, of course. I'd just like to add that even if the backslash isn't used as a separator in the Linux file structure, it may be useful as an escape character.
Let's say you have a folder called "my folder" in your home directory. The command
ls my folder
wont work. The shell will interpret the space between "my" and "folder" as a delimiter and start by looking for a directory called "my". To make it realize that the name of the folder is actually "my folder", you could type the name precisely like that, within quotes:
ls "my folder"
Or you could use the escape character "\" before the space instead. The backslash will make the shell interpret the space as just a space and not a delimiter:
ls my\ folder
will work correctly.
The \040 in dylan420's mtab is an example of an escape sequence of a different kind. In some programming languages it would also stands for a space (octal 40, decimal 32). This time it didn't work, which makes one suspect that his partitions hadn't been labelled in Linux.
And then the backslash is useful if you want to let the shell know that two consecutive lines should be interpreted as a single line.
Or try entering "echo uncle\" in a terminal, and hit Enter. You'll get the promt ">".
Then enter "V" and hit Enter again:
$ echo uncle\
> V
uncleV
So sometimes the backslash may have its place in Linux too.