How To: Escape Special Characters in MSBuild
Certain characters have special meaning in MSBuild project files. Examples of the characters include semicolons (;) and asterisks (*). In order to use these special characters as literals in a project file, they must be specified with the syntax %xx, where xx represents the ASCII hexadecimal value of the character. For a complete list of ASCII characters and their hexadecimal values, see ASCII Character Codes.
MSBuild Special Characters
One example of where special characters are used is in the Include attribute of item collections. For example, the following item collection declares two items: MyFile.cs and MyClass.cs.
If you want to declare an item that contains a semicolon in the name, you need to use the %xx syntax to escape the semicolon and prevent MSBuild from declaring two separate items. For example, the following item escapes the semicolon and declares one item named MyFile.cs;MyClass.cs.
To use an MSBuild special character as a literal character
Use the notation %xx in place of the special character, where xx represents the hexadecimal value of the ASCII character. For example, to use an asterisk (*) as a literal character, you would use the value %2A.