The "Small, Medium, Large, and X Large" folders refer to the design size of the runway lights commonly used as white marker lights on some aircraft, such as on the tail of the default FS9 Cessna C172SP. Some lights may appear bigger at various distances due to the nature of the sim. I use medium, which is sized close to the default FS9 halo texture, but designed a hair smaller intentionally. You may want to resize runway lights a half size bigger at a time (.50) to start with to get used to the scalar if you are unfamilier with it. The textures are 256 colors editing is not recommended.
The following are display values used in the FS9.cfg with the medium size texture.
These lines are intended for EXAMPLES ONLY!
(tastes may differ as well as hardware & drivers giving different outcomes)
------------------------> EXAMPLE <------------------------
