Field names with '.' vs. object data type hierarchy

[earl.lapus]

Object data type hierarchy is expressed by putting '.' characters between object names, as described here

I was wondering how this would affect fields in a document that have '.' characters between them but are not meant to be interpreted as hierarchical objects... just plain strings.

Example:
{
"time.out": 100
}

1. Is it recommended to avoid fields with '.' characters?
2. Is it possible to define a mapping template for my document that can distinguish between field names that ought to be interpreted as objects from those that must be interpreted as plain strings? - perhaps the regex option described here is a path I should take.

[rjernst (Ryan Ernst)]

Dots are always object hierarchy separators. There is no way to distinguish. In the case of "time.out", an object field call "time" would be created, with a subfield called "out" which is an int.