From the help for lookup tables:
“Acceptable parameter types are: NUMBER, LENGTH, AREA, VOLUME, ANGLE, and OTHER.
For example, a column may have the following header: TotalArea##AREA##INCHES to represent the total area in square inches.”
But from the help for type catalogues:
The following table includes a sample of the types of parameters supported in a type catalog.
Type of Parameter Parameter Declaration Notes
Text | param_name##OTHER## | |
Integer | param_name##OTHER## | |
Number | param_name##OTHER## | |
Length | param_name##LENGTH##FEET | |
Area | param_name##AREA##SQUARE_FEET | |
Volume | param_name##VOLUME##CUBIC_FEET | |
Angle | param_name##ANGLE##DEGREES | |
Slope | param_name##SLOPE##SLOPE_DEGREES | |
Currency | param_name##CURRENCY## | |
URL | param_name##OTHER## | |
Material | param_name##OTHER## | |
Yes/No | param_name##OTHER## | Defined as 1 or 0 with 1 equaling Yes and 0 equaling No. |
<Family Type> | param_name##OTHER## | Family name:type name with no file extension |
So it looks like Currency is not a valid parameter type in a lookup table but can be used in a type catologue.
For your example therefore, in a lookup table, I think you would use NUMBER without any units so something like GBP_Price##NUMBER##