diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 7ec76fc5b8e..073ee1c724e 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -40,7 +40,20 @@ After you have installed the necessary tools, you need to set up the repository.
 ## Workflow for submitting changes
 
 1. Create a new branch for your changes. Please use the following naming convention:
-   `fix/123` where `123` is the issue number you're working on.
+   - `{prefix}/{description}`
+   - `{prefix}/{issue-number}-{description}`
+   - `{prefix}/{third-party-repo-prefix}-{issue-number}-{description}`
+
+   Where `{prefix}` is:
+   - `fix` — complete fixes or rule additions
+   - `upd` — minor improvements (e.g. addressing omissions from previous commit, small documentation or comment edits)
+
+   Examples:
+   - `fix/12345`
+   - `fix/12345-example.com`
+   - `fix/ubo-12345-example.com`
+   - `upd/12345`
+
 1. Make your changes, test them and put them in the proper file or section of the file.
    - You can learn how to write filtering rules in the [How to write filter rules][how-to-write-filters] section.
    - Before creating any rules, please read and understand the current
@@ -63,6 +76,79 @@ After you have installed the necessary tools, you need to set up the repository.
    If AGLint passes, your PR will be reviewed by a maintainer.
 1. If the review is successful, your changes will be merged into the `master` branch.
 
+### Rule placement
+
+- By default, new rules should be placed at the top of the relevant section in the filter file.
+
+  ```diff
+  !NOTE: Regular rules
+
+  + example.org##.banner-ads
+  ||example.com/ads/*
+  ```
+
+- If the rule applies to a site for which a rules group exists, insert it **within that group**, rather than at the top
+  of the section.
+
+  ```diff
+  ! Example group
+  ||example.org/images/ads/*
+  + ||example.org/scripts/tracking.js
+  example.org##.example-ads
+  ```
+
+- For rules that share the same rule expression, depending on the type of rule,
+  add the new domain to the existing expression — either at the **beginning** or **at the end**,
+  rather than creating a new rule on a separate line.
+  This makes it easy to add a new domain consistently, treating them as a single rule.
+
+  **Important:** Don't insert a new domain at a random position in the middle of the list.
+
+  - For cosmetic rules – at the beginning of the rule:
+
+  ```diff
+  - example.com,example.org###ads
+  + test.com,example.com,example.org###ads
+  ```
+
+  - In general, for rules with `|` domains separator, add a new domain at the end:
+
+  ```diff
+  - adserver.com$domain=example.com|example.org
+  + adserver.com$domain=example.com|example.org|test.com
+  ```
+
+  - When the group contains both types, keep domain order consistent across all rules.
+
+    This is because only the separator differs (`,` vs `|`) —
+    consistent ordering makes it immediately clear that no domains are missing.
+
+  ```diff
+  -example.com,example.org###ads
+  +example.com,example.org,test.com###ads
+  -||example.com^$domain=example.com|example.org
+  +||example.com^$domain=example.com|example.org|test.com
+  -||ads.com^$domain=example.com|example.org
+  +||ads.com^$domain=example.com|example.org|test.com
+  ```
+
+### Commit message format
+
+- To close an associated issue, use:
+
+```text
+Fix #ISSUE_NUMBER example.org optional description
+```
+
+- For updates that do not require closing the issue (e.g. problematic issue, an issue with multiple reports, making
+  changes while solving the problem together with the user)
+
+```text
+Upd #ISSUE_NUMBER example.org description
+```
+
+If a commit is associated with an issue that has several reports, a link to the comment can be used as the description.
+
 ### Skipping checks
 
 If you need to skip running checks, you can do it in the following ways.