Unicode assigns character properties to each code point. These properties can be used to handle "characters" (code points) in processes, like in line-breaking, script direction right-to-left or applying controls. Slightly inconsequently, some "character properties" are also defined for code points that have no character assigned, and code points that are labeled like "<not a character>". The character properties are described in Standard Annex #44.
Properties have levels of forcefulness: normative, informative, contributory, or provisional. For simplicity of specification, a character property can be assigned by specifying a continuous range of code points that have the same property.