G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
G09F7/00—Signs, name or number plates, letters, numerals, or symbols; Panels or boards
G09F7/02—Signs, plates, panels or boards using readily-detachable elements bearing or forming symbols
G09F7/08—Signs, plates, panels or boards using readily-detachable elements bearing or forming symbols the elements being secured or adapted to be secured by means of grooves, rails, or slits
G09F7/10—Signs, plates, panels or boards using readily-detachable elements bearing or forming symbols the elements being secured or adapted to be secured by means of grooves, rails, or slits and slideably mounted