Although not the first writing system for sign languages (see Stokoe notation), SignWriting is the first to adequately represent facial expressions and shifts in posture, or to accommodate segments of speech longer than compound words and short phrases. It is the only system in regular use, used for example to publish college newsletters in American Sign Language, and has been used for captioning of YouTube videos. Sutton notes that SignWriting has been used or investigated in over 40 countries on every inhabited continent. However, it is not clear in how many of these countries it has been actually adopted by the Deaf community.
Words may be written from the point of view of the signer or the viewer. However, almost all publications use the point of view of the signer. Sutton designed the script to be written horizontally, like English, and from the point of view of the observer, but changed it to vertical and from the point of view of the signer, to conform to the wishes of Deaf writers.
The orientation of the palm is indicated by filling in the glyph for the hand shape. A hollow outline (white) glyph indicates that one is facing the palm of the hand, a filled (black) glyph indicates that one is facing the back of the hand, and split shading indicates that one is seeing the hand from the side. Although in reality the wrist may turn to intermediate positions, only the four orientations of palm, back, and either side are represented in SignWriting, as they are enough to represent sign languages.
If an unbroken glyph is used, then the hand is placed in the vertical (wall or face) plane in front of the signer, as occurs when finger spelling. A band erased across the glyph through the knuckles shows that the hand lies in the horizontal plane, parallel to the floor. (If one of the basic hand-shape glyphs is used, such as the simple square or circle, this band breaks it in two; however, if there are lines for fingers extended from the base, then they become detached from the base, but the base itself remains intact.)
The diagram to the left shows a B-hand (flat hand) in six orientations. For the three vertical orientations on the left side, the hand is held in front of the signer, fingers pointing upward. All three glyphs can be rotated, like the hands of a clock, to show the fingers pointing at an angle, to the side, or downward. For the three horizontal orientations on the right side of the diagram, the hand is held outward, with the fingers pointing away from the signer, and presumably toward the viewer. They can also be rotated to show the fingers pointing to the side or toward the signer. Although an indefinite number of orientations can be represented this way, in practice only eight are used for each plane—that is, only multiples of 45° are found.
There are over a hundred glyphs for hand shapes, but all the ones used in ASL are based on five basic elements:
A line halfway across the square or pentagon shows the thumb across the palm. These are the E, B, and (with spread fingers) 4 hands of fingerspelling.
These basic shapes are modified with lines jutting from their faces and corners to represent fingers that are not positioned as described above. Straight lines represent straight fingers (these may be at an angle to indicate that they are not in line with the palm; if they point toward or away from the signer, they have a diamond shape at the tip); curved lines for curved (cupped) fingers; hooked lines for hooked fingers; right-angle lines, for fingers bent at only one joint; and crossed lines, for crossed fingers, as shown in the chart at right. The pentagon and C are only modified to show that the fingers are spread rather than in contact; the angle is only modified to show whether the thumb touches the finger tips or juts out to the side. Although there are some generalizations which can be made for the dozens of other glyphs, which are based on the circle and square, the details are somewhat idiosyncratic and each needs to be memorized.
There are only a few symbols for finger movement. They may be doubled to show that the movement is repeated.
A solid bullet represents flexing the middle joint of a finger or fingers, and a hollow bullet represents straightening a flexed finger. That is, a 'D' hand with a solid bullet means that it becomes an 'X' hand, while an 'X' hand with a hollow bullet means that it becomes a 'D' hand. If the fingers are already flexed, then a solid bullet shows that they squeeze. For example, a square (closed fist, 'S' hand) with double solid bullets is the sign for 'milk' (iconically squeezing an udder).
A downward-pointing chevron represents flexing at the knuckles, while an upward-pointing chevron (^) shows that the knuckles straighten. That is, a 'U' hand with a down chevron becomes an 'N' hand, while and 'N' hand with an up chevron becomes a 'U' hand.
A zigzag like two chevrons (^^) joined together means that the fingers flex repeatedly and in sync. A double-line zigzag means that the fingers wriggle or flutter out of sync.
For movement with the left hand, the Δ-shaped arrowhead is hollow (white); for movement with the right hand, it is solid (black). When both hands move as one, an open (Λ-shaped) arrowhead is used.
As with orientation, movement arrows distinguish two planes: Movement in the vertical plane (up & down) is represented by arrows with double stems, as at the bottom of the diagram at left, while single-stemmed arrows represent movement parallel to the floor (to & fro). In addition, movement in a diagonal plane uses modified double-stemmed arrows: A cross bar on the stem indicates that the motion is away as well up or down, and a solid dot indicates approaching motion. To & fro movement that also goes over or under something uses modified single-stemmed arrows, with the part of the arrow representing near motion thicker than the rest. These are iconic, but conventionalized, and so need to be learned individually.
Straight movements are in one of eight directions for either plane, as in the eight principal directions of a compass. A long straight arrow indicates movement from the elbow, a short arrow with a cross bar behind it indicates motion from the wrist, and a simple short arrow indicates a small movement. (Doubled, in opposite directions, these can show nodding from the wrist.) A secondary curved arrow crossing the main arrow shows that the arm twists while it moves. (Doubled, in opposite directions, these can show shaking of the hand.) Arrows can turn, curve, zigzag, and loop-the-loop.
Six contact glyphs show hand contact with the location of the sign. That is, a handshape glyph located at the side of the face, together with a contact glyph, indicates that the hand touches the side of the face. The choice of the contact glyph indicates the manner of the contact:
Additional symbols are used to represent sign locations at the face or body parts other than the hands. A circle shows the head.