can be used in both environments without the final/non-final distinction. The capital letter upsilon (Υ) can occur in different stylistic variants, with the upper strokes either straight like a Latin Y, or slightly curled. The symbol ϒ (U+03D2) is designated specifically for the curled form (), used as a technical symbol, e.g. in physics. The letter phi can occur in two equally frequent stylistic variants, either shaped as (a circle with a vertical stroke through it) or as (a curled shape open at the top). The symbol (U+03D5) is designated specifically for the closed form, used as a technical symbol. The letter omega has at least three stylistic variants of its capital form. The standard is the "open omega" (Ω), resembling an open partial circle with the opening downward and the ends curled outward. The two other stylistic variants are seen more often in modern typography, resembling a raised and underscored circle (roughly o̲), where the underscore may or may not be touching the circle on a tangent (in the former case it resembles a superscript omicron similar to that found in the numero sign or masculine ordinal indicator; in the latter, it closely resembles some forms of the Latin letter Q). The open omega is always used in symbolic settings and is encoded in Letterlike Symbols (U+2126) as a separate code point for backward compatibility. Computer encodings For computer usage, a variety of encodings have been used for Greek online, many of them documented in . The two principal ones still used today are ISO/IEC 8859-7 and Unicode. ISO 8859-7 supports only the monotonic orthography; Unicode supports both the monotonic and polytonic orthographies. ISO/IEC 8859-7 For the range A0–FF (hex), it follows the Unicode range 370–3CF (see below) except that some symbols, like ©, ½, § etc. are used where Unicode has unused locations. Like all ISO-8859 encodings, it is equal to ASCII for 00–7F (hex). Greek in Unicode Unicode supports polytonic orthography well enough for ordinary continuous text in modern and ancient Greek, and even many archaic forms for epigraphy. With the use of combining characters, Unicode also supports Greek philology and dialectology and various other specialized requirements. Most current text rendering engines do not render diacritics well, so, though alpha with macron and acute can be represented as U+03B1 U+0304 U+0301, this rarely renders well: . There are two main blocks of Greek characters in Unicode. The