Forward Compatible

A forward compatible feature is a feature that will be available in future versions. In particular, it might be couple with a forward incompatible feature, which will be dropped, while the forward compatible feature will stay.

For example, PHP allows the increment of non-numeric strings. This feature might be deprecated, and could be removed in a future version (not defined at the time of writing). The functions str_increment() and str_decrement() were introduced in PHP 8.3. They can replace the current feature, and they will be available in the future versions, making them forward compatible.

<?php

$a = 't';
echo ++$a; //u

$a = str_increment($a);
echo $a; // v

?>

Related : Backward Compatible, Backward Incompatible, Deprecated, Upgrade, Version, delayedtargetvalidation