Rolemaster (3rd Edition) published in 1995 was named Rolemaster Standard System (RMSS) while Rolemaster (4th Edition) published in 1999 was named Rolemaster Fantasy Roleplaying (RMFRP).
The original Rolemaster rules were changed significantly around 1995 when the 3rd Edition was republished as Rolemaster Standard System (RMSS). The character skill development method was changed along with the skill bonuses allowing a character to buy ranks in either a skill or a category of skills. The combat sequence was revised. The spell list development was completely changed and the spell lists were adjusted and rebalanced, and some of the details of spell-casting were also changed. Rolemaster (3rd Edition), Rolemaster Standard System (RMSS), books typically have a dark brown border.
In 1999, the game was slightly restructured again when the 4th Edition, Rolemaster Fantasy Roleplaying (RMFRP), was published. Rolemaster (4th Edition), Rolemaster Fantasy Roleplaying (RMFRP), books typically have dark red border.
Note: This Rolemaster system of rules refers to most of the Rolemaster material that was published in 1995 or afterwards with the exception of the reprints of earlier material.