I do not intend to infringe on copyrights. I was wondering what is the reason for the creation of the following guidelines:
This is a shot of the book:
Graphic Design School: A Foundation Course for Graphic Designers Working in Print, Moving Image and Digital Media
Thanks to everyone in advance.
There are certain characters and filenaming conventions that are used by the OS or server software.
That looks like a cut and paste from Dropbox’s file naming protocols in order for them to transfer data across servers to get it to you.
Even on macs, you are not supposed to use those characters you are told to avoid.
A lot of my clients like to use government style file ID numbers that are something like Graphic.3.4.5.indd.
I have to either retype the file name or click on it in the folder to save-as because the program does not recognize anything as a filename beyond the first period following Graphic. It used to be, Indesign did not recognize image links if they had periods in them.
Because they are on Macs, they inadvertently use #, & and * all the time and sometimes only half of their packaged files get picked up by the software.
Just don’t.
What you really want to avoid is a backslash. That is an OS command level notation that can cause all sorts of wonderfully weird and wacky things to happen to your files. Do NOT write the date in your files using backslashes. Or periods.
Using spaces is pretty much ok, except for some servers.
The cap letters, some OS recognize them, some don’t. The ones that don’t will cause a file conflict if two files have the same name but one is capped.
When working anywhere that might be cross platform, and that includes handing off for print, work to a lower common denominator.
PrintDriver gave a detailed answer, so I just want to say that he’s right and I agree. It’s all about cross-platform compatibility.
On the web, for example, alpha-numeric characters are required, but some symbols, like underscores and hyphens are acceptable. Other characters, like slashes, colons, question marks, etc., have meanings in the context of the Internet, like directory changes and programming operators. Windows servers and Linux servers are different in the sense that one is not case sensitive while the other one is. I could go on, but you get the point.
I also recommend that students create a system for naming their files early on, and stick with it. Additionally, use file meta tags whenever possible, as this will save you when you are searching for things months or years later. 
