Brahmic family of abugidas. However, the other vowels were indicated with full letters, not diacritics or modification, so the system was essentially an alphabet that did not bother to write the most common vowel. Shorthand Several systems of shorthand use diacritics for vowels, but they do not have an inherent vowel, and are thus more similar to Thaana and Kurdish script than to the Brahmic scripts. The Gabelsberger shorthand system and its derivatives modify the following consonant to represent vowels. The Pollard script, which was based on shorthand, also uses diacritics for vowels; the placements of the vowel relative to the consonant indicates tone. Pitman shorthand uses straight strokes and quarter-circle marks in different orientations as the principal "alphabet" of consonants; vowels are shown as light and heavy dots, dashes and other marks in one of 3 possible positions to indicate the various vowel-sounds. However, to increase writing speed, Pitman has rules for "vowel indication" using the positioning or choice of consonant signs so that writing vowel-marks can be dispensed with. Development As the term alphasyllabary suggests, abugidas have been considered an intermediate step between alphabets and syllabaries. Historically, abugidas appear to have evolved from abjads (vowelless alphabets). They contrast with syllabaries, where there is a distinct symbol for each syllable or consonant-vowel combination, and where these have no systematic similarity to each other, and typically develop directly from logographic scripts. Compare the examples above to sets of syllables in the Japanese hiragana syllabary: か ka, き ki, く ku, け ke, こ ko have nothing in common to indicate k; while ら ra, り ri, る ru, れ re, ろ ro have neither anything in common for r, nor anything to indicate that they have the same vowels as the k set. Most Indian and Indochinese abugidas appear to have first been developed from abjads with the Kharoṣṭhī and Brāhmī scripts; the abjad in question is usually considered to be the Aramaic one, but while the link between Aramaic and Kharosthi is more or less undisputed, this is not the case with Brahmi. The Kharosthi family does not survive today, but Brahmi's descendants include most of the modern scripts of South and Southeast Asia. Ge'ez derived from a different abjad, the Sabean script of Yemen; the advent of vowels coincided with the introduction or adoption of Christianity about AD 350. The Ethiopic script is the elaboration of an abjad.