I was provided a schema withan attribute named “Type” provided byan ERP vendor. I needed to promote it for use in Send Port Filters and in a Correlation Set. I promoted the attribute and allowed BizTalk to create the promoted property “__Type” shown here:

“Type” is a reserved name. The Send Port Filter allows me to use this “__Type” Promoted Property.

But , . . . when I try to use this Promoted Property in a Correlation Set it gives me the following error.

Why does BizTalk default to the “__” prefix for reserved names, when it will not allow these prefixed names in Correlation Sets?