Reference
Glossary
These are the ideas that decide whether a conversion is correct, why a zip code loses its leading zero, why one emoji counts as two characters, why base64 is not encryption. Each entry is written to be read on its own.
- Base64
- A way of writing arbitrary bytes using 64 safe text characters.
- JWT (JSON Web Token)
- A claims token, commonly carried as a signed, three-part compact JWS.
- Lossy conversion
- A conversion where the output cannot express everything the input could.
- Minification
- Making code or data compact, with syntax-specific preservation limits.
- Prototype pollution
- Untrusted data writing to __proto__ and changing every object.
- ReDoS (regular expression denial of service)
- A regex that takes exponential time on input that almost matches.
- RFC 4180
- The specification that defines how CSV quoting works.
- Round trip
- Converting A to B and back to A, and checking you get the original.
- Surrogate pair
- Two code units used to represent one character above U+FFFF.
- Type inference
- Guessing whether the text "007" means a number, a string, or something else.
- URL encoding
- Percent-escaping the characters that would otherwise change a URL’s meaning.
- XXE (XML external entity)
- An XML document that makes the parser fetch a file or a URL.