Senior Member. The verb apply in this case is normally an intransitive verb,. e.g. The following rules are to apply (to the contract). If you say that the rules are to be applied, you are emphasising the fact that someone must apply or use these rules.

Will be applied to meaning?

apply to someone or something

[for rules, laws, etc.] to affect someone or something; to be relevant to someone or something.

Will be applying meaning?

to request something, usually officially, especially in writing or by sending in a form: By the time I saw the job advertised it was already too late to apply. I've applied for a new job with the local newspaper.