I believe they have the same meaning.

Electrode manufacturers often make several filler metals that meet the requirements to be classified as an EXXXX, EXXS-X, or EXXT-X. The manufacturer plays with the chemistry to provide the required mechanical properties, but the actual deposited chemistry may be slightly different for each of the filler metals with a different trade or brand name. Still, the filler metals meet the mechanical properties required of a certain AWS/ASME classification.

An example might be useful. When I am repairing a steel casting, I always ask for a chemical analysis to see what the sulfur content is. I then typically specify an E7018 low hydrogen electrode based on manganese content, I select a specific manufacturer and a specific brand name / trade name to ensure sufficient manganese to counter the affects of the sulfur. In this case, not all E7018 electrodes are created equal. When I specify the electrode, I am very specific because I am not only trying to ensure the proper mechanical properties, but I am also trying to ensure the filler metal is providing sufficient manganese to combine chemically with the sulfur in the base metal to prevent hot cracking.

I do the same thing when selecting a FCAW electrode. The manufacturers may produce several electrodes that meet the E71T-X classification, but they might require different shielding gases, provide slightly different deposited chemistry, or produce weld deposits with higher or low diffusible hydrogen content. Like E7018 SMAW electrodes, not all FCAW electrodes are created equally. When I have specific requirements or preference; I specify a certain brand name.

In the case of ASME, a filler metal that is not manufactured to a ASME specification and classification, i.e., a proprietary filler metal, the brand name / trade name becomes an essential variable. In other words, the WPS that is supported by a PQR that lists only the  brand name, the brand name or trade name because it does not meet an ASME specification or classification becomes an essential variable.

What edition of ASME Section IX are you using?

Best regards - Al