grep whole words made of only uppercase letters

Question

Seems like this is rather simple, but I\'m having trouble.

I have a text document that looks, for example, like this:

This is a
TEXT DOCUME

Answer 1

An "old school" RE would be fewer characters:

grep -o '[A-Z][A-Z]*' Untitled.txt

It uses the -o option to Only print matching words and matches against uppercase A through Z.

Adding -w to search words and -E to invoke the Extended regular expressions allows this one that is even shorter:

grep -woE '[A-Z]+\>' Untitled.txt