When you create a Microsoft word document and try to save it you don’t have to give the name for the doc as MS word takes whatever is there in the heading. For example if you have the heading of your doc as “My new doc” and click save button the name of the doc will be taken as “My new doc.docx”. You can very well change the name of the doc as you want it to be.
The name is all dependent on the heading, for example try the heading with a “-“(hyphen). i.e. “My – new doc” and click save button, the name of the doc will be taken as “My.docx” ignoring the rest of the words. So when a “-“(hyphen) is given in-between the letters they are ignored.