10 characters in the Vertical Forms Unicode block.
U+FE10PRESENTATION FORM FOR VERTICAL COMMAU+FE11PRESENTATION FORM FOR VERTICAL IDEOGRAPHIC COMMAU+FE12PRESENTATION FORM FOR VERTICAL IDEOGRAPHIC FULL STOPU+FE13PRESENTATION FORM FOR VERTICAL COLONU+FE14PRESENTATION FORM FOR VERTICAL SEMICOLONU+FE15PRESENTATION FORM FOR VERTICAL EXCLAMATION MARKU+FE16PRESENTATION FORM FOR VERTICAL QUESTION MARKU+FE17PRESENTATION FORM FOR VERTICAL LEFT WHITE LENTICULAR BRACKETU+FE18PRESENTATION FORM FOR VERTICAL RIGHT WHITE LENTICULAR BRAKCETU+FE19PRESENTATION FORM FOR VERTICAL HORIZONTAL ELLIPSIS