Does another party need to decode the url? What about using a dictionary for the top 10k seen starting combinations and then encode the rest?
What about run length encoding? 1-9 for positive sequences. a-i for negative sequences (max means pattern continues) and the rest for frequent patterns like alternating sequences, etc
9967b would be 24 yes, 1 no, 7 yes, 3 nos, 1 yes etc
Thanks. RLE is a hit-and-a-miss (101010101010 etc); top-k is heuristic-based. Those are viable solutions, nevertheless (esp, top-k). Puny Code, which DNS uses, I thought was pretty neat for fitting in a state-machine in printable characters. Takes a bunch of CPU resources to restore it, though.
I was wondering if there are other techniques that I may not be aware of.