In addition to custom types, you can also use common tags. As custom types are defined per category, common tags are common for every category (contracs and meetings) in your organization. So you can use them, for example, to index your documents. Tag a contract with common tag 1.2.3. and you can use that same tag in a meeting or in an HR document.
Please note: Common tags are visible for every user in your account, even if they don't have user rights to all categories.
Please note also: When you create a common tag in a document category (Contracts, Finance & Admin, HR, Other or Transfer Pricing), that tag will not be visible in any meeting category (Board, Shareholders, Other, Executive) until you take it into use in a meeting. This also works vice versa. This functionality is because we want to reduce excessive information i.e. we hide redundant info until you really need it.