Many (but not all) graphemes that are part of a writing system that encodes a full spoken language are included in the Unicode standard, which also includes graphical symbols. See:
The remainder of this list focuses on graphemes not part of spoken language-encoding systems.
The backtick ` is a typographical mark used mainly in computing. It is also known as backquote, grave, or grave accent.
The character was designed for typewriters to add a grave accent to a (lower-case) base letter, by overtyping it atop that letter. On early computer systems, however, this physical dead key+overtype function was rarely supported, being functionally replaced by precomposed characters. Consequently, this ASCII symbol was rarely (if ever) used in computer systems for its original aim and became repurposed in computer programming for many unrelated uses.
Star ratings are a type of rating scale using a star symbol or similar typographical mark. It is used by reviewers for ranking things such as films, TV shows, restaurants, and hotels. For example, a system of one to five stars is commonly used in hotel ratings, with five stars being the highest rating.
In typography, a bullet or bullet point, •, is a typographical mark used to introduce items in a list. For example:
The bullet symbol may take any of a variety of shapes, such as circular, square, diamond or arrow. Typical word processor software offers a wide selection of shapes and colors. Several regular symbols, such as * (asterisk), - (hyphen), . (period), and even o (lowercase Latin letter O), are conventionally used in ASCII-only text or other environments where bullet characters are not available. Historically, the index symbol ☞ (representing a hand with a pointing index finger) was popular for similar uses.