Not a maintenance contract. Updates, backups and response times are a separate matter in a separate document. Support is what comes after that, namely the content.
Not a substitute for a rebuild. When a site fundamentally no longer fits we say so instead of patching it in small steps for years. Twenty small fixes cost more than one clean rebuild.
And not support for sites we do not have full access to. If a previous provider grants only limited access we can do plenty but promise nothing. We settle that up front, not during the first urgent change.