Here you can name Custom Fields for Projects.
There are 25 fields available to you: fourteen Text fields (two of which are long text fields), four Number fields, four Date fields, and four Yes/No (Boolean). Short text fields have a limit of 300 characters, long text fields have a limit of 1000 characters.
Custom Fields can be used to store additional information for a project. They can also be used on Custom Reports, or could be used to pull text into your Project Number Format.