How to Explain Semantic Versioning Decisions in English

Deciding whether a change is a patch, a minor, or a major version bump under semantic versioning (semver) is often a judgment call, and explaining that judgment clearly in English — in a PR description, a changelog, or a maintainers’ discussion — is a skill of its own. This guide covers the vocabulary and reasoning patterns for making that call and communicating it convincingly.

Key Vocabulary

Patch version — a version bump for backward-compatible bug fixes that don’t change the public API’s behavior in any way callers could depend on. “This is a patch — we fixed an off-by-one error in the pagination logic, but the function signature and documented behavior are unchanged.”

Minor version — a version bump for backward-compatible new functionality, such as a new optional parameter or a new exported function. “This should be a minor bump, not a patch — we’re adding a new optional timeout parameter, which is new functionality, even though it doesn’t break existing callers.”

Major version — a version bump for changes that break backward compatibility, meaning existing code that uses the package may need to change to keep working. “Removing the deprecated fetchSync function is a breaking change, so this needs to be a major version, not a minor one.”

Public API surface — the parts of a package (exported functions, types, documented behavior) that external code is entitled to depend on; changes here are what semver actually tracks. “The internal refactor doesn’t touch the public API surface at all — everything we changed was in unexported helper functions, so this qualifies as a patch.”

Backward compatibility — the property that existing code using an older version of the API continues to work correctly with the new version. “We kept the old function as a deprecated alias to preserve backward compatibility, so this can ship as a minor version instead of a major one.”

Common Phrases

• “This should be a major bump — it removes a public function.”
• “I’d classify this as a minor version since it’s purely additive.”
• “Even though this looks small, it changes documented default behavior, so it needs to be a major version.”
• “This is internal-only and doesn’t touch the public API, so it’s a patch.”
• “We’re deprecating this in a minor release now, with removal planned for the next major.”

Example Sentences

Justifying a version choice in a PR description: “Bumping to 3.4.0 (minor) rather than a patch, since this adds a new retries option to the client constructor. It’s optional and defaults to the old behavior, so existing callers are unaffected, but it’s new surface area, which semver treats as minor rather than patch.”

Pushing back on a proposed version number in review: “I think this needs to be a major bump rather than minor. Changing the default timeout from 30s to 5s is backward-compatible in the sense that the function signature is the same, but it changes behavior that callers may be silently depending on — that’s exactly the kind of change semver’s major category exists for.”

Explaining a deprecation strategy: “We’re not removing oldMethod in this release — we’re marking it deprecated with a console warning, which is safe for a minor version. The actual removal will ship in the next major, giving users a full release cycle to migrate.”

Writing a changelog entry that explains the reasoning: ”### Changed (Minor) Added an optional strict flag to validate(). Existing calls without the flag are unaffected, which is why this ships as a minor rather than a major version.”

Professional Tips

• Justify your version choice by naming what changed in the public API surface, not just describing the code change — “this changes documented default behavior” is more convincing than “this is a bigger change.”
• When in doubt between patch and minor, ask: “does this add anything a caller could newly depend on?” If yes, it’s minor, even if no existing code breaks.
• When in doubt between minor and major, ask: “could this silently break someone relying on the old behavior, even without a signature change?” If yes, treat it as major.
• Use a deprecate-then-remove pattern for breaking changes when possible, and say so explicitly in the changelog — it signals to users that you’re being careful with their upgrade path.
• In review discussions, it’s fine to disagree about classification — just make sure you’re both arguing from “what does the public API surface look like to a caller,” not from “how big does this feel.”

Practice Exercise

1. Write a one-sentence justification for classifying a hypothetical change as a patch.
2. Write a review comment pushing back on a minor-vs-major classification, explaining your reasoning.
3. Write a changelog entry for a deprecation, including the planned removal version.