FMM Tourist Card, Custom Form questions

I am a permanent resident, so the number of days was not a question.

A friend will be arriving at ZIH international in a couple of weeks. I already gave them an FMM form in case they don’t have enough on the plane.

They are planning to stay for a month. I advised them to put a sticky note right onto the FMM form, “90 Dias, por favor”, so that there will be no ambiguity what they are requesting.

Yes, they plan to stay for a month, but if there are any flight changes, travel restrictions, etc., I want them to have the flexibility of additional days.