Tarjetas INAPAM (senior discounts)

INE is the voter card, Instituto Nacional Electoral.
CURP is similar to Social Security Number, Código Único de Registro de Población

Booth are only for Mexican Citizens.

That's not my understanding.
I have a CURP (Constancia De La Clave Unica De Registro De Población Para Extranjeros) issued when I received my Permanent resident card earlier this year.
I am not a Mexican Citizen.
I have heard several expat residents mention that they have INAPAM cards.
But this is the first time I've seen or heard anything about an INE card.
And that is what I am wondering about.