In Mexico I often see street addresses in the form "Calle Guadaloupe, 76bis" instead of "Calle Guadaloupe, 76" or something. I think I have also seen this in various other Latin American countries. Another common form I remember is "Calle Insurgentes 43 bis esquina 12c". I vaguely remember the doors being close to street corners too.
I've googled and asked people but not managed to get anywhere.
What does "bis" mean in this context?
Where street addresses are concerned there are many different systems even within the same country. In some places houses are numbered consecutively; if some building is then divided into two or more houses (or if different entrances are to have different numbers), one will find that, for example, the house between numbers 5 and 7 receives the number "5 bis".
In Argentina and other Latin American countries there is instead a system whereby blocks form a more-or-less regular grid and street numbers are assigned from fixed ranges. For example, in my street, the numbers from one block to the other run from 1500 to 1598 on the northern sidewalk and from 1501 to 1599 in the southern one. In this system, when a house needs a number, you can actually measure the distance from the corner and that, plus the corresponding offset, is its number. In this case you won't ever need something like a "bis". But sometimes a street is extended beyond its number zero in the "negative" direction. In some cities they just change the name of the street from that point on. In others they number the houses with "bis", with numbers growing in the opposite direction as the other part of the street (much like negative numbers).
bis
Del lat. bis 'dos veces'.
...
4. adj. U. pospuesto a un número de una serie para indicar que este sigue inmediatamente a ese mismo número ya empleado. Puerta 5 bis.
So, in this context it means there are two addresses with the same Street/Number, and this is referring to the second one. Similar to how A, B etc are used for apartments at the same address.
Note: this is general Spanish usage, not limited to Latin America.
