diff --git a/doc/contributor/PHP-EXT-install.yml.md b/doc/contributor/PHP-EXT-install.yml.md
index 5d9c7f2..64b56ba 100644
--- a/doc/contributor/PHP-EXT-install.yml.md
+++ b/doc/contributor/PHP-EXT-install.yml.md
@@ -29,16 +29,21 @@ already_avail: "{{ php_all_versions }}"
 **Example:** Overwriting `git_ref` for a specific version
 ```yaml
 already_avail: [5.2]
+
 all:
   type: git
   git_url: https://github.com/phalcon/cphalcon
   git_ref: master
+
 # PHP 8.1 is using a different git_ref
 8.1:
+  type: git
   git_ref: v1.0.0
+
 # PHP 8.0 is using a different git_ref dynamically with latest tag found
 # See the usage of supported shell code
 8.0:
+  type: git
   git_ref: $( git tag | sort -V | tail -1 )
 ```
 
@@ -53,7 +58,7 @@ The following keys can be added below: `all`, `8.2`, `8.1`, `8.0`, `7.4`, ...
 | `post`      | No       | Yes | Specify a shell command to be run after module installation. |
 | `build_dep` | No       | No  | Array Debian packages required to build the module (they won't be present in the final image - only used to built the module) If you don't need any, assign it an empty array: `build_dep: []`. |
 | `run_dep`   | No       | No  | Array Debian packages required for the module run-time (they won't be present during the build stage - only in the final image). If you don't need any, assign it an empty array: `run_dep: []`. |
-| `type`      | **Yes**  | No  | On of the following types to build the module: `builtin`, `pecl`, `git`, `custom`. |
+| `type`      | **Yes**  | No  | On of the following types to build the module: `builtin`, `pecl`, `git` or `custom`. |
 
 **Example:**
 ```yaml
@@ -65,6 +70,7 @@ all:
     rm -f /tmp/file.txt \
   build_dep: [libmcrypt-dev]
   run_dep: [libmcrypt4]
+
 8.1:
   type: builtin
   build_dep: []
@@ -82,9 +88,11 @@ all:
 ```yaml
 all:
   type: builtin
+
 8.1:
   type: builtin
   configure: --with-jpeg --with-png
+
 8.0:
   type: builtin
   configure: --with-jpeg
@@ -105,6 +113,7 @@ all:
   command: echo "/usr" | pecl install amqp
   build_dep: [librabbitmq-dev]
   run_dep: [librabbitmq4]
+
 5.5:
   type: pecl
   version: 1.9.3
@@ -124,16 +133,22 @@ all:
 **Example:**
 ```yaml
 already_avail: [5.2]
+
+# Default for all PHP versions if no overwrite exists
 all:
   type: git
   git_url: https://github.com/phalcon/cphalcon
   git_ref: master
-# PHP 8.1 is using a different git_ref
+
+# PHP 8.1 is overwriting the git_ref
 8.1:
+  type: git
   git_ref: v1.0.0
+
 # PHP 8.0 is using a different git_ref dynamically with latest tag found
 # See the usage of supported shell code
 8.0:
+  type: git
   git_ref: $( git tag | sort -V | tail -1 )
 ```
 
@@ -165,12 +180,12 @@ all:
 
 **Note:** All keys that support shell code can be written as a single line yaml definition or as a multi line yaml definition. Multi-line yaml definitions need a trailing `\` at the end of each line, including the last line.<br/>
 **Single-line:**
-```bash
+```yaml
 all:
   pre: VERSION="$( curl http://url | grep -Eo '[0-9.]+' )"
 ```
 **Multi-line:**
-```bash
+```yaml
 all:
   pre: |
     VERSION="$( \
@@ -183,7 +198,7 @@ all:
 
 **Note:** All keys that support shell code also support to write multiple shell commands. If you use multiple shell commands, you need to separate them with `&&`.<br/>
 **Single-command:**
-```bash
+```yaml
 all:
   pre: |
     VERSION="$( \
@@ -192,7 +207,7 @@ all:
     )" \
 ```
 **Multi-command:**
-```bash
+```yaml
 all:
   pre: |
     URL="http://url" \
diff --git a/doc/contributor/PHP-TOOL-install.yml.md b/doc/contributor/PHP-TOOL-install.yml.md
index 7d52c56..2e3bb22 100644
--- a/doc/contributor/PHP-TOOL-install.yml.md
+++ b/doc/contributor/PHP-TOOL-install.yml.md
@@ -9,3 +9,219 @@ PHP Tools: `install.yml`
 
 
 # Tool definition: `install.yml`
+
+
+## Top level defines
+
+| Yaml key        | Description |
+|-----------------|-------------|
+| `check`         | A check command to test that the tool has been installed correctly. |
+| `all`           | Is generic for all PHP versions and will be used whenever no specific version is defined. |
+| `7.2`           | A version specific block for PHP 7.2. Its child keys will overwrite what has been defined in `all`. |
+**Example:**
+```yaml
+check: yq --version 2>&1 | grep -E '[0-9][.0-9]+' || (yq --version; false)
+
+# Default for all PHP version if no overwrite exists
+all:
+  type: pip
+  version:
+  build_dep: []
+  run_dep: []
+  pre:
+  post:
+
+
+# PHP 5.2 is overwriting the version of yq to install
+5.2:
+  type: pip
+  version: 0.1.0
+```
+
+
+## Second level defines
+
+The following keys can be added below: `all`, `8.2`, `8.1`, `8.0`, `7.4`, ...
+
+| Yaml key    | Required | Supports<br/>Shell code | Description |
+|-------------|----------|-------------------------|-------------|
+| `pre`       | No       | Yes | Specify a shell command to be run before module installation. |
+| `post`      | No       | Yes | Specify a shell command to be run after module installation. |
+| `build_dep` | No       | No  | Array Debian packages required to build the module (they won't be present in the final image - only used to built the module) If you don't need any, assign it an empty array: `build_dep: []`. |
+| `run_dep`   | No       | No  | Array Debian packages required for the module run-time (they won't be present during the build stage - only in the final image). If you don't need any, assign it an empty array: `run_dep: []`. |
+| `type`      | **Yes**  | No  | On of the following types to build the module: `apt`, `composer`, `npm`, `pip`, `rubygem` or `custom`. |
+
+**Note:** When using `type: custom`, all data needs to be installed into `/usr/local/bin` as only this directory is copied into the next docker stage during multi-stage build.
+
+
+## Second level defines for `type: apt`
+
+| Yaml key    | Required | Supports<br/>Shell code | Description |
+|-------------|----------|-------------------------|-------------|
+| `package`   | Yes      | No                      | Specify the Debian apt package to install |
+
+**Example:**
+```yaml
+all:
+  type: apt
+  package: netcat
+
+5.3:
+  type: apt
+  package: netcat.traditional
+```
+
+
+## Second level defines for `type: composer`
+
+| Yaml key    | Required | Supports<br/>Shell code | Description |
+|-------------|----------|-------------------------|-------------|
+| `package`   | Yes      | No                      | Specify the Composer package name to install |
+| `composer`  | Yes      | No                      | Specify the composer version to use for installation: `1` or `2` |
+| `version`   | No       | Yes                     | Specify the Composer package version to install |
+| `binary`    | No       | Yes                     | Specify the composer relative binary path to symlink to `/usr/loca/bin/` |
+| `flags`     | No       | Yes                     | Add composer flags to `composer require` |
+
+**Example:**
+```yaml
+all:
+  type: composer
+  composer: 2
+  package: laravel/installer
+  binary: bin/laravel
+
+7.1:
+  type: composer
+  version: 2.3.0
+  binary: laravel
+```
+
+
+## Second level defines for `type: npm`
+
+| Yaml key    | Required | Supports<br/>Shell code | Description |
+|-------------|----------|-------------------------|-------------|
+| `package`   | Yes      | No                      | Specify the NPM package name to install |
+| `version`   | No       | Yes                     | Specify the NPM package version to install |
+| `binary`    | No       | Yes                     | Specify the NPM relative binary path to symlink to `/usr/loca/bin/` |
+
+**Example:**
+```yaml
+all:
+  type: npm
+  package: pm2
+  binary: pm2
+  version:
+```
+
+
+## Second level defines for `type: pip`
+
+| Yaml key    | Required | Supports<br/>Shell code | Description |
+|-------------|----------|-------------------------|-------------|
+| `version`   | No       | Yes                     | Specify the Pip package version to install |
+
+The PyPI package name defaults to the name specified in `options.yml`.
+
+**Example:**
+```yaml
+all:
+  type: pip
+  version:
+  build_dep: []
+  run_dep: []
+  pre:
+  post: |
+    ln -s pwncat /usr/local/bin/netcat \
+```
+
+
+## Second level defines for `type: rubygem`
+
+| Yaml key    | Required | Supports<br/>Shell code | Description |
+|-------------|----------|-------------------------|-------------|
+| `package`   | Yes      | No                      | Specify the Rubygem package name to install |
+| `version`   | No       | Yes                     | Specify the Rubygem package version to install |
+
+**Example:**
+```yaml
+all:
+  type: rubygem
+  package: mdl
+  build_dep: [ruby-dev]
+  run_dep: [ruby]
+
+7.2:
+  type: rubygem
+  version: 0.11.0
+  pre: |
+    gem install chef-utils -v 16.6.14 \
+```
+
+
+## Second level defines for `type: custom`
+
+| Yaml key    | Required | Supports<br/>Shell code | Description |
+|-------------|----------|-------------------------|-------------|
+| `command`   | Yes      | Yes                     | Custom command to install a tool. |
+
+**Note:** When using `type: custom`, all data needs to be installed into `/usr/local/bin` as only this directory is copied into the next docker stage during multi-stage build.
+
+**Example:**
+```yaml
+all:
+  type: custom
+  command: curl -sS -k -L --fail -L "${PHP_CS_FIXER_URL}" -o /usr/local/bin/php-cs-fixer
+  pre: PHP_CS_FIXER_URL="https://cs.symfony.com/download/php-cs-fixer-v3.phar"
+  post: chmod +x /usr/local/bin/php-cs-fixer
+
+7.3:
+  type: custom
+  pre: PHP_CS_FIXER_URL="https://cs.symfony.com/download/php-cs-fixer-v2.phar"
+```
+
+
+## Usage of shell code
+
+### Single-line vs Multi-line
+
+**Note:** All keys that support shell code can be written as a single line yaml definition or as a multi line yaml definition. Multi-line yaml definitions need a trailing `\` at the end of each line, including the last line.<br/>
+**Single-line:**
+```yaml
+all:
+  pre: VERSION="$( curl http://url | grep -Eo '[0-9.]+' )"
+```
+**Multi-line:**
+```yaml
+all:
+  pre: |
+    VERSION="$( \
+      curl http://url \
+      | grep -Eo '[0-9.]+' \
+    )" \
+```
+
+### Single-command vs Multi-command
+
+**Note:** All keys that support shell code also support to write multiple shell commands. If you use multiple shell commands, you need to separate them with `&&`.<br/>
+**Single-command:**
+```yaml
+all:
+  pre: |
+    VERSION="$( \
+      curl http://url \
+      | grep -Eo '[0-9.]+' \
+    )" \
+```
+**Multi-command:**
+```yaml
+all:
+  pre: |
+    URL="http://url" \
+    && VERSION="$( \
+      curl "${URL} \
+      | grep -Eo '[0-9.]+' \
+    )" \
+    && echo "${VERSION}" \
+
+```