At each commit, the number of odd characters increases...Take a look at Dictionary.class.st for exampleon line 10:
https://github.com/pharo-project/pharo/blob/bc8b9658958f4464189cf3e7fffd8c9bf775f85f/src/Collections-Unordered/Dictionary.class.st
I���������������������������������� am use when we need a collection of objects which I can access with a key. For example if you associate some words with a definition, the word will be the key and the definition will be the value. Both of them can be any kind of objects.