Typography is performed by typesetters, compositors, typographers, graphic artists, art directors, and clerical workers. Graduates of the Printing House found work at New York newspapers as compositors and pressmen. Nowadays DRM is also used by several Wayland compositors, including Weston reference compositor. They were hindered by occasional shortages of suitable paper, ink, compositors and printers. Wayland compositors communicate with Wayland clients over the Wayland display server protocol. The rules were embodied in a four-page booklet of typographic instructions for editors and compositors. Display servers that implement the Wayland display server protocol, are called Wayland compositors. In the 1880s Elmira S. Cleaveland and Hattie E. Dennis worked as compositors. Wayland compositors (e.g. Weston) and kmscon depend on kernel mode setting via ioctl. XKB is also used by Wayland compositors and kmscon. At the start of the 20th Century, ITU membership was primarily compositors and mailers. He is known for having premiered many current Spanish compositors works. He was the author of "Hart's Rules for Compositors and Readers", first issued in 1893. The following year, it was joined by the News Society of Compositors. Certain compositors can choose to add custom interfaces to provide specialized or unique features.