wax gradually moved down the social hierarchy from monarchs and bishops to great magnates, to petty knights by the end of the 12th century, and to ordinary freemen by the middle of the 13th century. They also came to be used by a variety of corporate bodies, including cathedral chapters, municipalities, monasteries etc., to validate the acts executed in their name. Traditional wax seals continue to be used on certain high-status and ceremonial documents, but in the 20th century they were gradually superseded in many other contexts by inked or dry embossed seals and by rubber stamps. While many instruments formerly required seals for validity (e.g. deeds or covenants) it is now unusual in most countries in the west for private citizens to use seals. In Central and Eastern Europe, however, as in East Asia, a signature alone is considered insufficient to authenticate a document of any kind in business, and all managers, as well as many book-keepers and other employees, have personal seals, normally just containing text, with their name and their position. These are applied to all letters, invoices issued, and similar documents. In Europe these are today plastic self-inking stamps. Notaries also still use seals on a daily basis. At least in Britain, each registered notary has an individual personal seal, registered with the authorities, which includes his or her name and a pictorial emblem, often an animal—the same combination found in many seals from ancient Greece. Practices Seals are used primarily to authenticate documents, specifically those which carry some legal import. There are two main ways in which a seal may be attached to a document. It may be applied directly to the face of the paper or parchment (an applied seal); or it may hang loose from it (a pendent seal). A pendent seal may be attached to cords or ribbons (sometimes in the owner's livery colors), or to the two ends of a strip (or tag) of parchment, threaded through holes or slots cut in the lower edge of the document: the document is often folded double at this point (a plica) to provide extra strength. Alternatively, the seal may be attached to a narrow strip of the material of the document (again, in this case, usually parchment), sliced and folded down, as a tail or tongue, but not detached. The object in all cases is to help ensure authenticity by maintaining the integrity