In Nutshell, this blog post explains how to block file types at document library level in a website. Also this post is a documentation for my Codeplex project, which enables in a particular document library in SharePoint website.
Generally, in SharePoint collaborative portals administrators like to have better control over the file types being uploaded in a document library.
Unfortunately, SharePoint provides a way to block file types at application level. Refer MSDN article for more details.
Since, this can be a common requirement across different SharePoint projects, I created a SharePoint project called SPBlockFileTypes on CodePlex.com Below is the detailed documentation about this project.
This project allows website managers to block file types being uploaded in SharePoint document library.
This project includes a single SharePoint feature.
On activation this feature adds a custom action under site administration in site settings page. This custom action link will be visible to only users with manage web permissions. This link points to the application page which website manager can manage and configure allowed or blocked file types of a document library.
On deactivating this feature, all the blocking rules on document library set by the website manager will be removed.
You can view this project on codeplex site here.
You can also Download the Source code for this project.