Creating and using Calculated Columns in your ContentTypes are a bit tricky.
First off the syntax for defining a Calculated column is like
<Field ID="{Some GUID}" Name="Name" Group="GroupName" Type="Calculated" DisplayName="Display Name" StaticName="Name" FromBaseType="TRUE" ResultType="Number/Text" ReadOnly="TRUE">
<Formula>Some Forumula</Formula>
<FieldRefs>
<FieldRef Name="Name of Field Referred"/>
</FieldRefs>
</Field>
For the calculated column to work in multiple ContentTypes each of the fields referred in calculation should be a part of the ContentType and ...
<the most vital part as it caused me a lot of pain yesterday and took a while to figure out >
... the referred columns should have the same Display Name in the ContentType as when Columns were originally defined. That is you cant use a column referred in a ContentType and change its Display Name within the ContentType.
tags:
Sharepoint,
ContentTypes,
Calculated Columns,
WSS
Cross-posted from tariqayad.com