NOTE: Using a blue, purple, or red colorbox obscures unvisited, visited, and missing wikilinks, respectively, as these are the default link colors for most users.
Legends and keys
The colorbox template is widely used to annotate complex tables in which editors have used color to group like entries. The editor uses the background-color style to color individual cells in the table and then adds a legend consisting of colorboxes at the beginning or end of the table explaining the meanings behind the color scheme. The editor may also add symbols like a caret (^), dagger/obelisk (†), double dagger/diesis (‡), or asterisk (*) to call attention to the different meanings.
Text marker examples
Using a black colorbox with text markers obscures the text as the default style foreground color for most users is black.
The HTML code * must be used to create the asterisk as Wikipedia will treat the typed asterisk as an indented bullet point.