I will have to re-read the letter, but this looks like a branch specific letter that has the aim of clarifying their policy.
For example, at Circuit Assemblies, the Per Capita rate is never supposed to be announced. The fact that this letter dated 03/27/2017 mentions to not do that, in bold, may mean that some had actually announced it! Ha!
Also, the inclusion of initials "SDF:SDD" before the date, indicate that this was drafted at the branch level. I don't know the boys down in Texcoco well enough to tell you who that is, but those are the initials of the Bethelite who drafted the letter and his assistant who typed it.
Very interesting stuff. It only further confirms how Assemblies are a cash making scheme for the Org.
Si sobran fondos y la cuenta del circuito sobrepasa los fondos que excedan el objetivo de saldo, se donará a la obra mundial el sobrante
All excess funds go to the "world wide work".