In reference to political campaign signs, the size is not regulated. The definition of a political sign (see 16.02.360) does not include a size allowance, as well as 16.03110, but the code does state that political signs shall be limited to one sign per candidate per street frontage for each private lot. Political signs are not allowed on vacant lots without permission from the property owner (see 16.03.120).
Other signs, like freestanding or wall signs, size is regulated by zone and lot or business size.