Accessor Notation is a new feature in PRPL. It provides a simpler way to access the properties of units than in CRPL. Whereas in CRPL one would get/set unit attributes with:

# Set Unit Attribute
<-UID CONST_UNITATTRIBUTE <-Value SetUnitAttribute
# Get Unit Attribute
<-UID CONST_UNITATTRIBUTE GetUnitAttribute

PRPL allows a much faster notation styled after object property accessors in object-oriented programming languages:

# Set Unit Attribute
<-Value ->UID.Attribute
# Get Unit Attribute
<-UID.Attribute

This has the advantage of being easier to read and identify, as well as the fact that all valid property tokens are not case-sensitive:

# These are treated the same
<-UID.Attribute
<-UID.ATTRIBUTE

Note that Ships, Particles and Units are considered distinct; their IDs are generally referred to as SID, PID and UID respectively, and are each obtained with different commands. See GetAllShipsInRange, GetParticlesInRange and GetAllUnitsInRange.