Wikipedia:Contents/Reference/Topics

General reference lists:
Reference of organizations
- Libraries:
Reference works:
Research tools and resources:
Standards:
- Common standards
- Numbering schemes
- International standards:
  - List of International Organization for Standardization standards
  - ISO 639 language names
  - ISO 3166 country codes
  - Time zones
  - Country calling codes
  - Internet TLDs
  - Plastic recycling codes
- United States standards:
  - Federal Standard 1037C (Glossary of telecommunication terms)
  - FIPS country codes
  - U.S. postal abbreviations
- Size, measurement and conversions
  - SI:
  - Unit conversions:
    - Unusual units of measurement
    - Humorous units of measurement
  - Orders of magnitude:
  - Specific measures: