Baybayin or Alibata (known in Unicode as the Tagalog script) is a pre-Hispanic Philippine writing system that originated from the Javanese script Old Kawi. The writing system is a member of the Brahmic family (and an offshoot of the Vatteluttu alphabet) and is believed to be in use as early as the 14th century. It continued to be in use during the Spanish colonization of the Philippines up until the late 19th Century. The term baybayin literally means spelling. Closely related scripts are Hanunoo, Buhid, and Tagbanwa.
The writing system is an abugida system using consonant-vowel combinations. Each character, written in its basic form, is a consonant ending with the vowel “A”. To produce consonants ending with the other vowel sounds, a mark is placed either above the consonant (to produce an “E” or “I” sound) or below the consonant (to produce an “O” or “U” sound). The mark is called a kudlit. The kudlit does not apply to stand-alone vowels. Vowels themselves have their own glyphs. There is only one symbol for D or R as they were allophones in most languages of the Philippines, wherein D fell in initial, final, pre-consonantal or post-consonatal positions and R in intervocalic positions.
In its original form however, a stand-alone consonant (consonants not ending with any vowel sound) cannot be produced, in which case these were simply not written and the reader would fill in the missing consonants through context. This method, however, was particularly hard for the Spanish priests who were translating books into the native language. Because of this Father Francisco Lopez introduced his own kudlit in 1620 that eliminated the vowel sound. The kudlit was in the form of a “+” sign, in reference to Christianity. This cross-shaped kudlit functions exactly the same as the virama in the Devanagari script of India. In fact, Unicode calls this kudlit the Tagalog Sign Virama.