The ! prefix will unignore the file.

Else sub projects (main dir has sub dirs with own pom files - sub modules) targets are not ignored.

This extension is an alternative scheduler to build multi-module Maven projects.
It stores and updates timing for every build run in .mvn/timing.properties.

http://takari.io/book/30-team-maven.html#takari-smart-builder

The popular build plugin org.codehaus.mojo:buildnumber-maven-plugin stores the build number it managers in a file named buildNumber.properties.

'mvn versions:use-latest-versions' generates 'pom.xml.versionsBackup' file, because '-DgenerateBackupPoms=true' is default; see http://mojo.codehaus.org/versions-maven-plugin/use-latest-versions-mojo.html#generateBackupPoms

Maven Release Plugin provides a standard mechanism to release project 
artifacts.

During the various phases of the execution the plugin create various 
files, especially if you do a dry run that allows you to see the changes
that the plugin will perform on your pom files

	mvn release:prepare -D dryRun=true

It will create

- `release.properties` - copy of the properties to be used
- `pom.xml.releaseBackup` - the pom.xml prior to any changes
- `pom.xml.tag` - the pom.xml as it will look when tagged
- `pom.xml.next` - the pom.xml as it will look for the next iteration