I am comparing NewsFeedDirect to Elektron MRN: I see for the same story:

NewsFeedDirect gives

<Product>

<Code>NS:RTRS</Code>

<Code>NP:C</Code>

<Code>NP:CGO</Code>

<Code>NP:D</Code>

<Code>NP:DNP</Code>

<Code>NP:E</Code>

<Code>NP:ELN</Code>

<Code>NP:G</Code>

<Code>NP:GFN</Code>

<Code>NP:GRO</Code>

<Code>NP:M</Code>

<Code>NP:MNI</Code>

<Code>NP:MTL</Code>

<Code>NP:NAT</Code>

<Code>NP:NAW</Code>

<Code>NP:O</Code>

<Code>NP:OIL</Code>

<Code>NP:PGE</Code>

<Code>NP:PSC</Code>

<Code>NP:RNP</Code>

<Code>NP:SOF</Code>

<Code>NP:T</Code>

<Code>NP:U</Code>

<Code>NP:USDN</Code>

</Product>

with 24 Codes

But, Elektron MRN gives:

"audiences": ["NP:C", "NP:CGO", "NP:D", "NP:DNP", "NP:E", "NP:ELN", "NP:G", "NP:GFN", "NP:GRO", "NP:M", "NP:MNI", "NP:MTL", "NP:NAT", "NP:NAW", "NP:O", "NP:OIL", "NP:PGE", "NP:PSC", "NP:RNP", "NP:SOF", "NP:T", "NP:U", "NP:USDN"]

with 23 NPs

Elektron is missing NS:RTRS. What does NS mean? What does RTRS mean?

Is "audiences" explained in the MRN specs? If so could you give a link to the specs? Thanks