Special marks don't have primary designation as navigational marks; they are used to denote special areas or objects, about what mariner is informed from charts or other navigational publications.
These marks are yellow colored, can have top sign in shape of letter 'X', also yellow colored. If they are equiped with light, it is yellow. To avoid confusion between white and yellow light during poor visibility, ritham of yellow light must be diferent of one used for white light.
Shape of special marks should not be diferent in shape from oteher navigatioanl marks.
To emphasize meaning of special marks, letters or numbers can be added to special marks.
Description of special marks:
Mark on top (if exists)
sign 'X' yellow painted;
what ever, but diferent from other navigational marks;
Light (if exists)
what ever, exept like cardinal marks, mark of alone danger and mark of safe waters;