Use:

ItemName To find a partial match

• The search: Runecloth
• Would return: Any item that contains the string "Runecloth" in it.

ItemId To find a specific item by Id

• The search: 14048
• Would return: The item [Bolt of Runecloth]

=ItemName To search for an exact match

• The search: =Runecloth Bandage
• Would return: The item [Runecloth Bandage]