stargazer_table_layout_characters: stargazer: table layout characters
In ChandlerLutz/stargazer: Well-Formatted Regression and Summary Statistics Tables

The following character strings can be used in the table.layout and omit.table.layout arguments of the stargazer command.

`"-"`	single horizontal line
`"="`	double horizontal line
`"-!"`	mandatory single horizontal line
`"=!"`	mandatory double horizontal line
`"l"`	dependent variable caption
`"d"`	dependent variable labels
`"m"`	model label
`"c"`	column labels
`"#"`	model numbers
`"b"`	object names
`"t"`	coefficient table
`"o"`	omitted coefficient indicators
`"a"`	additional lines
`"n"`	notes
`"s"`	model statistics