I noticed the following when reading the documentation
Parameters with a hashtag have a different meaning with the function last - they denote the Nth previous value, so given the values 3, 7, 2, 6, 5 (from the most recent to the least recent):
last(/host/key,#2) would return '7'
last(/host/key,#5) would return '5'
While this example is technically correct, it would be much better if the example values had been 30, 70, 20, 60, 50 to eliminate any possibility for confusion/misunderstanding. As it currently is indexes 2 and 5 also overlaps values 2 and 5 which has a tiny potential for confusion.
This is a relative minor issue, but I would like to bring it up as an improvement issue not only for this single instance, but I assume the documentation contains multiple cases like this.
Us developers are typically not very creative when coming up with example data when writing documentation or unit tests, so if for instance testing our new and shiny library code we might write tests with book id 1, author id 1 and user id 1 if no specific thought is given to which values to use...
However tests are just so much easy to read if some though is given to which values are used, e.g. user ids are selected from 10-99, author ids from 100-999 and book ids from 1000-9999. And this applies to examples in documentation as well.