In the Thinfinity® Remote Desktop Server profiles editor "Resources" tab you will find the following options:
The Thinfinity.RemoteDesktop.Server.ini configuration file location depends on the Windows version Thinfinity® Remote Desktop Server is running at:
C:\ProgramData\Cybele Software\Thinfinity\Remote Desktop Server\Thinfinity.RemoteDesktop.Server.ini
C:\Documents and Settings\All Users\Application Data\Cybele Software\Thinfinity\Remote Desktop Server\Thinfinity.RemoteDesktop.Server.ini (older Windows versions)
Inside the ini file, create an [AutoDownload] section and use the 'Exclusion' key with the values that you want to exclude using Glob Expression Syntax (standard DOS mode), separated by the "|" char. You can also use the regular expression notation to indicate which files to exclude, except for the single pipe character, which is reserved for Thinfinity® Remote Desktop Server to notice separation between exclusion rules. Use the double pipe character, instead, within the regex for the "or" operator.
Take a look at the following example. Notice the use of ":" at the beginning of the jpg exclusion rule and the double pipe to note that files starting with the letter a or the letter b will be excluded.