Merge branch 'ayduns-master-patch-57524' into 'master'

Add historical PHP & MySQL compatibility info

See merge request documentation/docs/installation!24

docs/general/requirements.md

@@ -68,6 +68,18 @@ It is also important to ensure that the same PHP extensions/modules are loaded o
 | PHP 7.0 | **incompatible** | incompatible as of 5.25.0 |
 | PHP 5.6 | **incompatible** | **incompatible** |
 
+??? info "Historical PHP Versions"
+    The table below gives information on PHP minimum and recommended version compatibility for old versions of CiviCRM:
+
+    | CiviCRM Version          | PHP Minimum Version | PHP Recommended Version |
+    | ------------------------ | ------------------- | ----------------------- |
+    | 5.1 - 5.5                | 5.5                 | 7.0                     |
+    | 5.6 - 5.9                | 5.5                 | 7.1                     |
+    | 5.10 - 5.13              | 5.6                 | 7.2                     |
+    | 5.14 - 5.23              | 7.0                 | 7.2                     |
+    | 5.24                     | 7.0                 | 7.3                     |
+    | 5.25 - Current           | 7.1                 | 7.3                     |
+
 ### PHP Extensions
 
 To install these extensions, you will typically install a separate package within your server's package manager (e.g. `apt-get` on Ubuntu).
@@ -112,6 +124,14 @@ Other database servers (such as PostgreSQL) are not compatible with CiviCRM.
 
 Your MySQL version should be **5.7.5 or greater** or MariaDB **10.0.2 or greater**.  As of version 5.28 the minimum install version for CiviCRM is 5.6 users on versions before that are advised to upgrade their MySQL instance to a recommended version. CiviCRM may not run correctly on MySQL 5.6 as these versions don't support some of the functionality CiviCRM uses to ensure that database actions don't compete for the same resources.
 
+??? info "Historical MySQL Versions"
+    The table below gives information on MySQL minimum and recommended version compatibility for old versions of CiviCRM:
+
+    | CiviCRM Version          | PHP Minimum Version | PHP Recommended Version |
+    | ------------------------ | ------------------- | ----------------------- |
+    | 5.26 - 5.27              | 5.5                 | 5.7                     |
+    | 5.28 - Current           | 5.6.5               | 5.7                     |
+
 #### MySQL 8
 
 As of version 5.24 CiviCRM has been shown to be able to run on MySQL 8 through the execution of our test matrix. Not all of the Content Management Systems support MySQL 8, CiviCRM MySQL 8 support is being tracked in this [open issue for MySQL 8 support](https://lab.civicrm.org/dev/core/issues/392). It is also worth knowing that both [Backdrop](https://forum.backdropcms.org/forum/installing-backdrop-1126-mysql-8-sqlmode-cant-be-set-value-noautocreateuser) and [Drupal 7](https://www.drupal.org/project/drupal/issues/2978575) have open issues with regards to MySQL 8 support. [Drupal 8](https://www.drupal.org/docs/8/system-requirements/database-server) [supports MySQL 8 as of version 8.6](https://www.drupal.org/project/drupal/issues/2966523), Current versions of WordPress and [Joomla](https://docs.joomla.org/Joomla_and_MySQL_8) appear to be compatible with MySQL 8