Belgian banknotes with dates not in Numista ?

Hello , i have a few banknotes that i can not catalogue in Numista since i do not find the date in the lists. Am i a poor investigator ?? Please help me to explain how i can find them.  Thanks a lot in advance

Top is 1971. Bottom is 1938. The date is the last 2 digits of one of the serials

N#206236

1971-Jul-01 not on the list

N#208273

1938-Jun-02 not on the list

Thanks for the help! 

One more question : must ( can )  i ad these to the list ?

Or is it ‘ not done’  ?

Yes you can.  Click the Modify icon on the top right. Use this post in the Sources box or just upload your pictures.

N#208273

I have one not in the list dated 23 Feb., 1942 

BELGIUM | 1942 | 100 Francs / 20 Belgas / French on Obverse

As explained by rsirian1 2 years ago, you can add the missing date yourself. See his post above yours 

marnik.dejonckheere

Hello , i have a few banknotes that i can not catalogue in Numista since i do not find the date in the lists. Am i a poor investigator ?? Please help me to explain how i can find them.  Thanks a lot in advance

You are not missing anything. Many Belgian notes do not use a printed date as a catalog key. Numista often lists them by series, signature pair, or law date, not the year shown on the note. Check the signatures, printer, and series number, then match those fields instead of the visible date.