documentation/dev-guide.md

 ---
 title: Developer guide
 ---
+
 # Table of contents
 [[_TOC_]]
 
@@ -80,3 +81,58 @@ Example issue title :
 [feature] Implement algorithm Foo bar
 
 Select an issue template (feature request or bug report) and fill all fields as clearly and concisely as possible.
+
+# Push rules
+
+The online repository has rules on the format of commit messages as well as branch names. 
+
+## Branch names
+Branch names should always be created from issues, and the Gitlab repository settings are such that their suggested name should always match the branch name push rule.
+The branch name rule in the public repository is set with the following regular expression:
+
+`^(main|develop|(\d+)-hotfix-.+|(\d+)-feature-.*|release-v\d+\.\d+\.\d+)$`
+
+Examples of valid branch names are listed below. You can test the regular expression above by copy/pasting it in https://regex101.com/ and tweaking your text until it matches the expression. 
+
+Valid branch names:
+- main
+- develop
+- \<issue number\>-hotfix-\<arbitrary text\> (e.g. 2-hotfix-pvgis-api)
+- \<issue number\>-feature-\<issue title\> (e.g. : 69-feature-grassim-refactoring, generated from issue #69 )
+- release-v\<major version\>.\<minor version\>.\<patch version\> (e.g. release-v1.2.4)
+
+## Commit rule
+This rule exists to prevent cryptic commit messages, often pushed when in a rush and thus degrading the traceability of the commits in the repository's history.
+
+A commit message should comprise the following : 
+- title line with 3 possibilities: 
+	1. standard commit: commit type in square brackets (e.g. \[feature\] or any of the list of commit types) followed by the title, briefly describing the content : "[feature] Apply multiplying factor to GHI"
+	2. merge commit from a Gitlab merge request : "Merge branch 'source' into 'target' "
+	3. merge commit from remote into local branch : "Merge branch '\<branch name\>' of gitlab.uliege.be:deal-public/branch into branch"
+- blank line
+- commit message body
+- possibly "Closes # \<issue number\>" but this is automatically handled in Gitlab merge requests
+
+
+The commit message rule is set with the following regular expression:
+
+`^(?:\[(feature|fix|chore|refactor|docs|style|test|perf|ci|build|revert)\] .+|Merge branch '.*' .+)\n\n(.+)`
+
+Examples of valid commit messages are listed below. You can test the regular expression above by copy/pasting it in https://regex101.com/ and tweaking your text until it matches the expression.
+
+### Standard commit message
+
+[fix] Error in azimut/elevation computation
+
+The x and y component were reversed in foo.py, method get_azimut_elevation(). I fixed it by [blablabla]...]. Now the results are correct as validated by foobar other method.
+
+
+### Merge request commit message
+Merge branch '69-feature-grassim-refactoring' into 'develop'
+
+Describe the new feature, refer relevant commits, etc.
+
+### Merge remote branch into local branch
+Merge branch '\<branch name\>' of gitlab.uliege.be:deal-public/branch into branch
+
+Some description.
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