Are colons allowed URIs?

Question

I thought using colons in URIs was "illegal". Then I saw that vimeo.com is using URIs like http://www.vimeo.com/tag:sample.

1. What do you feel about the usage of colons in URIs?
2. How do I make my Apache server work with the "colon" syntax because now it's throwing the "Access forbidden!" error when there is a colon in the first segment of the URI?

Answer 1

Colons are allowed in the URI path. But you need to be careful when writing relative URI paths with a colon since it is not allowed when used like this:

<a href="tag:sample">

In this case tag would be interpreted as the URI’s scheme. Instead you need to write it like this:

<a href="./tag:sample">

Answer 2

Also note the difference between Apache on Linux and Windows. Apache on Windows somehow doesn't allow colons to be used in the first part of the URL. Linux has no problem with this, however.