I am developing a asp.net website. When I used the CSS property "word-wrap", VIsual Studio 2010 is showing a warning: Validation (CSS 2.1) 'word-wrap' is not a known CSS property name. 

When I tested the website, it is working fine. However, can there be any issue in using this property ignoring the warning?

This is a symptom of a wider migration towards distributed version control systems.

Some websites which traditionally hosted non distributed VCS (eg Codeplex & SourceForge) were a little slow in adding support for DVCS (eg Git or Mercurial). So, people who wanted to use DVCS for their project were forced to migrate their projects over to the providers which supported them (eg Github or BitBucket). Github was one of the first to offer DVCS support and so naturally a lot of people migrated their code there in order to take advantage of it.

Those other websites are only now starting to catch up to DVCS (Codeplex for example now supports Mercurial & Git), but they are still a way behind in terms of features such as forking and submitting pull requests. To really take advantage of DVCS Github and Bitbucket are still the best options.
