In one way I totally agree.
Although knowing that the \ character is an 'escape' character used for entering literal characters or characters by their ascii code, etc is actually basic knowledge when you work with JScript (and many many other languages for that matter).
An example (where the double backslash is used) wouldn't hurt though.
But I think a "more in depth explaination" of the use of characters and stuff and especially the backslash in JScript is not on its place there; that belongs in the 'string' section in the Jscript documentation...
EDIT: Spelling mistake fixed. Thx markee, keep them coming