A Consent is a contract between the owner of a property and one or more additional parties explicitly agreeing to any of a wide range of services or circumstances (i.e. construction matters, purchasing, selling, etc.).
A Notice is the written notification or announcement from one party to another of something impending (i.e. foreclosure, inspection, etc.).
A Permission is a written authorization granting permission for something to occur (i.e. sub-let, construction, installation, etc.).
An Estoppel is a signed statement verifying that certain declarations of fact are true, as of the date of the statement, and can be relied upon as such by another party (i.e. a signed disclaimer, or lease).
You can find consents, notices, permissions & estoppels by clicking here.