Consider the diagram above and the note at the bottom of the map. It is using a prototype ('A prototype'), inheriting the $Color 'green'. If the the note has its $Color set to 'orange', the new colour—by being set local to the note—overrides the prototype-inherited colour. Note the $Color data in the Displayed Attributes is listed in bold as it is now set specifically for this note. In Tinderbox terminology this is a local value.
You may now see this is also how a prototype alters the cascade. If a prototype sets a local value, it breaks inheritance from above, yet creates a new one below it in the cascade. Thus a local value in a note using a prototype also breaks the cascade, i.e. the note now does not use the prototype's cascaded value.