Autodesk Revit MEP

[#1]

Hello

I am trying to set a template fille up so that ABS fittings sizes are restricted to the sizes on a lookup table.  On the template I have transitioned from 100mm down to 65mm.  Revit has 'invented' a custom bush that isn't in the sizes I have entered in the lookup table.  Is there a way to force Revit to only use fitting sizes from the lookup table?

i.e. this would normally be something like 2 bushes in total to transition between the 100mm (4") to the 65mm (2 1/2") since my supplier doesn't make 100mm to 65mm bushes.  The Lookup table used in the bush family is pointing correctly to my custom lookup table.

[#2]

Not sure about the restriction that I wanted BUT I have found a workaround - using the link below(showing use of IsCustom family parameter) I have made any 'custom' fittings that aren't found in the Lookup csv file appear RED.  This is very useful to me.

http://www.andekan.com/blog/2011/11/25/family-feedback-mechanisms-part-2/