Often you have files in your subversion directiory which you do not want to commit / check-in. Such files could be compiled files, intermediate files used for data processing etc. Subversion provides a simple way to exclude such files. The good news is that it allows you to specify them using patterns, so you don't have to individually specify them.

Revision number of a file is an important information. Two most common uses are in serialization and in making version specific database upgrades for an application. I am using it for the later. Here is a simple way how you can add revision number (Id, Date, Author and HeadURL) automatically to your source files.