Reference
Lookup tables for the things that are quicker to check than to remember: character codes, DNS record types, HTTP headers, regular-expression syntax and how the hash algorithms compare. Each one is a complete table rather than a summary, so it is worth bookmarking.
Reference tables
6- ASCII Table All 128 ASCII codes in decimal, hex, octal and binary.
- HTML Entities Named and numeric character references, grouped by what they are for.
- DNS Record Types What each DNS record type does and when you need it.
- HTTP Headers The request and response headers worth knowing, grouped by job.
- Regex Cheat Sheet Regular expression syntax, grouped by what you are trying to match.
- Hash Algorithm Comparison Which hash to use for what, and which are broken.
Searchable lookups
All tools →Two subjects are covered by a searchable tool rather than a static table, because filtering hundreds of entries beats scrolling them.