To be honest, I wouldn't add something to an original artefact that wasn't there before.
This is especially true in this particular case. I'm going to go out on a limb here and say that this RZM tag is fake. Why?
Even if it cannot be ruled out that there were red tags without serial numbers in later wartime, this statement does not apply to the early blue examples.
The serial number is missing here.
In addition, the font type is wrong, as we are talking about the period up to spring 1938. It should be in Fraktur. Antiqua is only plausible after January 1941.
The printing is strangely unclean and a bit blurred, see the ‘e’ in Hersteller and the blue stripes on the right.
For comparison, on the left the first blue RZM tag with TA for textile badge manufacturers, directly from tge 1936 RZM regulations, and on the right an original armband with an authentic blue A4 tag at one pfennig. The new code A4 was published in RZM-Mitteilungsblatt No. 10/1935 of 9 March 35.
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