In the Argentine Republic (LU) the first letter
of the suffix of a colleague´s license allows to recognise from what province
he is transmitting; for example, in LU8ADX, the
first letter after the prefix is "A",
which is the letter for Capital Federal.
The Argentine Radio Club LU4AA grants a certificate called TRA, "Toda la República Argentina" (All of the provinces of Argentina) to the stations that have confirmed all of the provinces. For further details, please refer to the page of certificates (Only in Spanish).
I thank Adriana Oviedo for translating this page.