Does having multiple dots in a filename bad?

Is there any organization or articles that says we can or should not have multiple dots in filename? I'm really confuse if I should use dot in PHP files, I migh开发者_如何学Ct break some rules or standards.

A filename with multiple dots does not break any PHP naming conventions, because file names are not PHP variable names; they belong to the OS really and PHP only sees them as strings.

EDIT

I looked around and found cases for multiple dots: version numbers and dates. There has been some discussion as to whether these increase or decrease SEO value but I have not found anything conclusive. It does show however that they are used.

Tip: Try the following Google search: seo periods in filenames