usethis supports semantic versioning, which is described in more detail in the version section of R Packages. A version number breaks down like so:

<major>.<minor>.<patch>       (released version)
<major>.<minor>.<patch>.<dev> (dev version)

use_version() increments the "Version" field in DESCRIPTION, adds a new heading to NEWS.md (if it exists), and commits those changes (if package uses Git). It makes the same update to a line like PKG_version = "x.y.z"; in src/version.c (if it exists).

use_dev_version() increments to a development version, e.g. from 1.0.0 to 1.0.0.9000. If the existing version is already a development version with four components, it does nothing. Thin wrapper around use_version().

## Usage

use_version(which = NULL)

use_dev_version()

## Arguments

which

A string specifying which level to increment, one of: "major", "minor", "patch", "dev". If NULL, user can choose interactively.

if (FALSE) {