Symfony service strict parameter

Question

Does anyone know what the "strict" parameter does when injecting a service in Symfony ?

For example:

<service ...>
    <argument type="service" id="whatever" strict=false />
</service>

Thank you!

Answer 1

I did some research and it's a leftover from Symfony 2.8 as this comment suggests:

Note: The $strict parameter is deprecated since version 2.8 and will be removed in 3.0.

Since 3.0 the parameter doesn't exist as well as the deprecation warning but classes YamlFileLoader and XmlFileLoader still read it even though the Reference class takes only two arguments.

So, this parameter does nothing :).