The list can use numerical, alphabetic, or alpha-numeric identifiers. There are a number of different arrangements of alphabetic, numeric, and punctuation symbols on keys. An advantage of numeric codes over alphabetic codes is script (writing system) independence. The system consists of a combination of logophonetic, consonantal alphabetic, and syllabic signs. The script is syllabic, not alphabetic. Alphabetic letters may be symbols for sounds. Phonemes are considered to be the basis for alphabetic writing systems. In other alphabetic systems, diacritical marks may perform other functions. Today, the link between alphabetic and numeral sampi is universally accepted. English spelling is based on the alphabetic principle. This loosely corresponds to "shallow" orthographies in alphabetic writing systems. There are three ways to deal with the umlauts in alphabetic sorting. The macron is also used in German lute tablature to distinguish repeating alphabetic characters. The small number of alphabetic characters needed for European languages was an important factor. Uptake of handwriting recognition among users who use alphabetic scripts has been slower.