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CONTRIBUTING.md

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+# Contributing to iTop
+
+You want to contribute to iTop? Many thanks to you! 🎉 👍
+
+Here are some guidelines that will help us integrate your work!
+
+
+## Contributions
+
+### Subjects
+You are welcome to create pull requests on any of those subjects:
+
+* 🐛 `:bug:` bug fix
+* 🔒 `:lock:` security
+* 🌐 `:globe_with_meridians:` translation
+
+If you want to implement a **new feature**, please [create a corresponding ticket](https://sourceforge.net/p/itop/tickets/new/) for review.   
+If you ever want to begin implementation, do so in a fork, and add a link to the corresponding commits in the ticket. 
+
+### License
+iTop is distributed under the AGPL-3.0 license (see the [license.txt] file), 
+your code must comply with this license.
+
+If you want to use another license, you may [create an extension][wiki new ext].
+
+[license.txt]: https://github.com/Combodo/iTop/blob/develop/license.txt
+[wiki new ext]: https://www.itophub.io/wiki/page?id=latest%3Acustomization%3Astart#by_writing_your_own_extension
+
+
+## Branch model
+
+TL;DR:
+> **create a fork from iTop main repository,  
+> create a branch based on either release branch if present, or develop otherwise**
+
+We are using the [GitFlow](https://nvie.com/posts/a-successful-git-branching-model/) branch model. That means we have in our repo those 
+main branches:
+
+- develop: ongoing development version
+- release/*: if present, that means we are working on a beta version
+- master: previous stable version
+
+For example, if no beta version is currently ongoing we could have:
+
+- develop containing 2.8 version
+- master containing 2.7 version
+
+In this example, when 2.8 beta is shipped that will become:
+
+- develop: 2.9 version
+- release/2.8: 2.8 beta
+- master: 2.7 version
+
+And when 2.8 final will be out:
+
+- develop: 2.9 version
+- master: 2.8 version
+
+
+## Coding
+
+### PHP styleguide
+
+Please follow [our guidelines](https://www.itophub.io/wiki/page?id=latest%3Acustomization%3Acoding_standards).
+
+### Tests
+
+Please create tests that covers as much as possible the code you're submitting.
+
+Our tests are located in the `test/` directory, containing a PHPUnit config file : `phpunit.xml.dist`.
+
+### Git Commit Messages
+
+* Describe the functional change instead of the technical modifications
+* Use the present tense ("Add feature" not "Added feature")
+* Use the imperative mood ("Move cursor to..." not "Moves cursor to...")
+* Limit the first line to 72 characters or less
+* Please start the commit message with an applicable emoji (following the [Gitmoji guide](https://gitmoji.carloscuesta.me/).). For example :
+    * 🌐 `:globe_with_meridians:` for translations
+    * 🎨 `:art:` when improving the format/structure of the code
+    * ⚡️ `:zap:` when improving performance
+    * 🐛 `:bug:` when fixing a bug
+    * 🔥 `:fire:` when removing code or files
+    * 💚 `:green_heart:` when fixing the CI build
+    * ✅ `:white_check_mark:` when adding tests
+    * 🔒 `:lock:` when dealing with security
+    * ⬆️ `:arrow_up:` when upgrading dependencies
+    * ⬇️ `:arrow_down:` when downgrading dependencies
+    * ♻️ `:recycle:` code refactoring
+    * 💄 `:lipstick:` Updating the UI and style files.
+
+## Pull request
+
+When your code is working, please:
+
+* stash as much as possible your commits,
+* rebase your branch on our repo last commit,
+* create a pull request.
+
+Detailed procedure to work on fork and create PR is available [in GitHub help pages](https://help.github.com/articles/creating-a-pull-request-from-a-fork/).