Questão jurídica principal
Whether the challenged decision was void or should be quashed because it bore the wrong letterhead and an unclear signature.
Decisão extraída
The decision was valid: the dispositive part showed that the Department of the Interior decided, and the signature was by an authorized head of division.
Fundamentação extraída
A wrong letterhead is not a ground of invalidity, let alone nullity, where the dispositive and signature clearly identify the competent authority and lawful delegation exists.