Appendages
Rule 4a. The appendage should be designed in unity with, and proportionately related to, the vertical or horizontal character of the primary mass, but subordinated to it.
Rule 4b. The appendage should have the appearance of flowing smoothly and, if possible, tangentially from the primary mass.
Rule 4c. The appendage should, if possible, echo or repeat some lines similar in character and direction to those of the primary mass.