By default, solution files in sub-directories of the Windows "Program Files" directory are considered both solution files and shared system files. As shared system, symbols declared within the files can appear with other stable symbols in italics, denoting the fact the symbols have not been overridden.
Users of Unreal Engine 4 who installed a binary distribution of the engine to a sub-directory of the Window "Program Files" directory, and who have enabled stable symbols in italics, see engine symbols in italics.
Prevent designation of any solution files from being designated shared system by modifying the registry:
HKCU\Software\Whole Tomato\Visual Assist X\<IDE spec>\ProgramFilesDirsAreSystemIncludes = 00
Set to 01 to restore default behavior.
Visual Assist build 2217 and older
Solution files, whether or not in a sub-directory of the Windows "Program Files" directory, are never considered shared system files.