Now that is odd...

During REM period of sleep, your Broca and Wernicke lobes are not active, thus, you are incapable of understanding language and comprehension of it.

However, you are still able to recognise numbers and text along with the emphasis of it; what the symbols and words remind you of. Also, words that are always associated with a person or thing such as names or titles. Example: You see a general store and the title on top of it is "Mikes Mart" or "7/11" whatever, you just always know anyway so it is insignificant to truly lay any attention into.

In the "Psychopathology of Everday Life", Sigmund Freud talks about the phenomen of supposively arbitrarily and spontaneously producing numbers. Through psychoanalysis, however, the numbers are proven to be produced from a history of psychological motivations; what the numbers remind the individual of and the cognitive empathy. Example: When I tried this experiment on myself, I commonly came up with the numbers 11 and 77. These numbers represent me and my gf (111 is "my" number and 77 is the number she wears when playing baseball and what not).

So, it boils down to the essential question: What do the numbers remind you of? What do you think of when you look at the numbers?

Maybe it's the way they were presented, or perhaps they remind you of a phone number or birthdate?

Hope I've been enlightening.