How to create blank value in product rule

Summary:

Making an attribute in item rule creation non-mandatory or being able to propose a blank value.

Content (required):

Hello,

Customer needs to have item descriptions where sometimes a value is blank.

The third square bracket is the attribute and currently in product rule it is always mandatory. How is it possible to add a value which is blank?

Version (include the version you are using, if applicable):

Code Snippet (add any code snippets that support your topic, if applicable):

[Item].[FG Item Desc].[Fiber Type] + " " + [Item].[FG Item Desc].[Fiber] + " " + [Item].[FG Item Desc].[Main Fiber %] + " " + [Item].[FG Item Desc].[Second Fiber Desc] + " " + [Item].[FG Item Desc].[Second Fiber ] + " " + [Item].[FG Item Desc].[Third Fiber Desc] + " " + [Item].[FG Item Desc].[Third Fiber] + " " + [Item].[FG Item Desc].[Application] + " " + [Item].[FG Item Desc].[Count] + "/" + [Item].[FG Item Desc].[PLY]