Percentage encoding

You would have come across a URL string that appears as

https://example.com/project-search?search_api_fulltext=&f%5B0%5D=species%3AAtlantic%20Salmon

As you would already seen %20 many times, that is a space.  Commonly seen in file names either documents or images.

However, what about the others.  Off the top do you know what %3D is?  Maybe, but I didn't.  Below is a quick guide to percentage encoding table:

However, for a far more in depth overview of percentage encoding go to https://en.wikipedia.org/wiki/Percent-encoding.