local is the most common symbol extension. It means that the variable is local to the cog and is not given a value in the level's .jkl file. This doesn't mean that if you leave out the local, the variable will be global and accessible to all cogs.If a symbol does not have the local extension and its cog is defined in the cogs section of a JKL, then the symbol can be given an initial value from the JKL (see the Symbols General document). Example:
int integer local
desc is short for description. It is used to comment on a symbol. Example:thing item desc=powerup
Mask is used to assign Mask Flags to a symbol. The Mask Flags control which messages from the symbol are received by the cog. The symbol type descriptions explain the effect of Mask Flags on each symbol type. Mask Flags can only be used with objects whose values are passed from the level's JKL. Example:Symbols of types that can send messages have default Mask Flags. The mask entension is used to reset the Mask Flags, so the defaults are overwritten.
sector sec1 mask=0x4
Linkid provides a way to assign an ID to a symbol that generates messages. This ID can be retrieved in messages sent by the object with GetSenderID(). Linkids can only be used with objects whose values are passed from the level's JKL. Example:sector sec1 linkid=1
Nolink blocks the messages sent by a symbol from being received by its cog. Nolink is only used with symbols whose value is passed from a level's JKL. Example:sector sec1 nolink