Glossary

Plain-language definitions of SEO terms used across the blog.

Cocoa timestamp (Apple Core Data time)

Apple's Cocoa or Core Data timestamp counts seconds, or nanoseconds in newer iMessage stores, since 2001-01-01 00:00:00 UTC instead of the Unix epoch.

FILETIME (Windows timestamp)

Windows FILETIME is a 64-bit count of 100-nanosecond intervals since 1601-01-01 00:00:00 UTC, used in NTFS, the registry and Outlook MSG properties.

JID (Jabber ID, WhatsApp identifier)

A JID is an XMPP-style address, user@domain, that WhatsApp uses to identify contacts, groups and broadcast lists in its databases and protocol traffic.

Message-ID (email header)

The Message-ID header is a globally unique identifier for one email, written in angle brackets by the originating client or first mail server that handled it.

Received header (email)

A Received header is a trace line each mail server prepends when it accepts a message, recording the sending host, the receiving host and a timestamp.

Snowflake ID (Discord, Twitter/X)

A snowflake is a 64-bit identifier whose upper bits encode its creation time in milliseconds, used by Discord and Twitter/X for users, messages and channels.