OpenType is a cross-platform font format developed by Adobe and Microsoft in the late 1990s. It has the faculty to include an expanded character set and layout features to provide richer linguistic support and/or advanced typographic control such as various numeral styles, ligatures, small capitals and contextual substitutions. OpenType supports Unicode, which enables the fonts to contain more than 65,000 glyphs while ʻPostScript®ʼ fonts are technically limited to a maximum of only 256 characters. This means that a user does not need to have separate fonts for Western, Central European or other languages, but could have one single file which supports all these encodings. OpenType fonts, as a new industry standard, will work in all applications, however only some applications take profit of the advanced OpenType features, other applications will only use the first 256 characters.
OpenType Features
picto All Caps [CPSP]
picto2 Case Sensitive Forms [CASE]

With both OpenType and other fonts, this function formats the text in uppercase. With OpenType fonts, it also applies ‘Case Sensitive Forms’ OpenType layout features for alternate uppercase positioning of punctuation, and spacing designed for all-cap use (not when text is typed in caps).

All Caps [CPSP]
picto Small Capitals [SMCP]
picto2 All Small Caps [C2SC]

There are two ways of applying ‘Small Capitals.’ The first one replaces only lower case letters with small caps. The second method replaces also capital letters with small capitals, and replaces regular quotation marks, exclamation points and question marks with lowered small caps variations.

Small Capitals [SMCP]
picto Standard Ligatures [LIGA]

Standard ligatures are glyphs which are designed to improve the kerning and readability of certain letter pairs. For example, when this feature is activated, typing ‘f’ and ‘i’ will automatically produce the ‘fi’ ligature.

Standard Ligatures [LIGA]
picto Discretionary Ligatures [DLIG]

This features activates discretionary ligatures. It will activate all other 
designed ligatures that are not classified as standard ligatures.

Discretionary Ligatures [DLIG]
picto Tabular Lining Figures [TNUM/LNUM]
picto2 Proportional Lining Fig. [PNUM/LNUM]
picto3 Tabular OSF [TNUM/ONUM]
picto4 Proportional OSF [PNUM/ONUM]

Tabular figures are of equal width and needed when they must line up from one line to the next. Proportional figures have varying widths. Lining figures are all the same height. Oldstyle figures have varying height.

Tabular Lining Figures [TNUM/LNUM]
picto Fractions [FRAC]

Turns on fractions. All OpenType fonts from Optimo have at least three basic pre-built fractions (1/2, 1/4, 3/4).

Fractions [FRAC]
picto Numerator [NUMR]
picto2 Denominator [DNOM]

This feature will replace all styles of figures with their numerator or denominator alternates. These are the same glyphs that are used to create pre-build fractions, their vertical position remains within the capital letters height.

Numerator [NUMR]
picto Ordinals [ORDN]

Replaces regular glyphs (not numerals) to with their matching superiors glyphs. All Optimo fonts have the masculine and feminine ordinals required for Spanish segunda/segundo (2a, 2o).

Ordinals [ORDN]
picto Superscript/Superior [SUPS]

Substitutes all figures and lowercase letters (if present) with their superior letterforms, wich can be used for footnotes references, etc. These designed glyphs match the weight of the regular letters and numbers, they are spaced more generously and therefore are more legible than scaled characters.

Superscript/Superior [SUPS]
picto Subscript/Inferior [SINF]

Substitutes all figures with their inferiors letterforms, commonly used for chemical compounds, and as mathematical exponents. These designed glyphs match the weight of the regular letters and numbers, they are spaced more generously and therefore are more legible than scaled characters.

Subscript/Inferior [SINF]
picto Stylistic Alternates [SALT]
picto2 Stylistic Set 1 [SS01]

This feature will activate some alternative glyphs which can be activated by turning on ‘Stylistic Alternates’ in Adobe Illustrator and Photoshop, or on the other hand by selecting ‘Stylistic Set 1’ in InDesign.

Stylistic Alternates [SALT]
picto Contextual Alternates [CALT]

This feature substitutes a glyph or a combination of glyphs that only occur depending on what letters are nearby. For instance the letter ‘x’ placed after a number will be replaced by the ‘multiplication’ glyph. If the font has arrows, you will be able to display them by typing a combination of letter on your keyboard like ‘hyphen + greater-than’ or ‘hyphen + less-than.’ This feature is usually on by default in Adobe applications.

Contextual Alternates [CALT]