- From: r12a via GitHub <sysbot+gh@w3.org>
- Date: Sat, 25 Apr 2020 08:29:23 +0000
- To: public-css-archive@w3.org
It seems we are fumbling about in the dark a bit wrt what specific technical problems generic fonts solve. Perhaps the following will throw in a chink of i18n light that may help. **The following is all about situations where if you pick up a fallback generic font you’d really want it to be of a particular type.** I try to show some examples of situations where falling back to an arbitrary font could be problematic because the writing style performs a practical function that either suits it for a particular audience/region (identity) or helps distinguish some content from other content (semantics). In other words, the differences pointed to here are not just cosmetic. There can also be ‘mechanical’ implications, in that some writing styles use a different character repertoire than others, meaning that text may not render properly on fallback, or may be adapted to specific behavioural features (such as the differences in justification behaviours for naskh, ruq’ah, and nastaliq fonts). Follow the links for examples. This is not an exhaustive list. ## Adlam (Pular) See https://r12a.github.io/scripts/adlam/#writing_styles A **_cursive writing style_** (ie. one where the letters are joined up) is the norm. An **_unjoined writing style_** is used for display fonts in books and articles to clearly distinguish titles. It is also used for social reasons in educational contexts (because the unconnected script is easier to learn). Fallback to a cursive font would reduce the distinctiveness of titles, but would also have an impact on readability for educational materials. ## N’Ko (Maninka, Bambara, Dyula, ...) See https://r12a.github.io/scripts/nko/#sample (i have no example of unjoined yet) A **_cursive writing style_** (ie. one where the letters are joined up) is the norm. An **_unjoined writing style_** is used for display fonts in books and articles to clearly distinguish titles. (Don’t know about educational usage.) Fallback to a cursive font would reduce the distinctiveness of titles. ## Arabic (Standard Arabic, Azerbaijani, Central Kurdish, Hausa, Kashmiri, Luri, Mazanderani, Punjabi, Northern Pashto, Persian, Western Panjabi, Dari, Sindhi, Saraiki, Uyghur, Urdu, Northern Uzbek, Malay,…) Arabic orthographies can be grouped into a number of writing styles, some of which are more common for particular languages, while others can be used interchangeably for the same language. Sometimes the variations are adapted to usage, for example book text vs. inscriptions; sometimes the variants reflect regional, cultural or stylistic calligraphic preferences. For a brief introduction to font styles, with examples, see https://w3c.github.io/alreq/#h_writing_styles. Not all writing styles are described here. The **_naskh writing style_** is the most prominent style for the Arabic language, and has become the default form of Arabic language content in most contexts. See https://r12a.github.io/scripts/arabic/#sec_naskh_style The **_nasta’liq writing style_** is the standard way of writing Urdu and Kashmiri. It is also often a preferred style for Persian text. Key features include a sloping baseline for joined letters, and overall complex shaping and positioning for base letters and diacritics alike. There are also distinctive shapes for many glyphs and ligatures. See: https://r12a.github.io/scripts/arabic/urdu#writing_styles Falling back to an arbitrary font (usually naskh) significantly affects the identity and the readability of the content for speakers of Urdu and Kashmiri. The **_ruq’ah writing style_** is commonly used in education, in official documents, and for every-day writing. It is known for its clipped letters composed of short, straight lines and simple curves, as well as its straight and even lines of text. It is a functional style of writing that is quick to write and easy to read. It also doesn’t extend baselines, like a naskh font does. In 2010's rebranding of Amman, Jordan, a ruq'ah font family was created to serve as an italic face alongside a naskh regular font. See https://r12a.github.io/scripts/arabic/#sec_ruqah_style Falling back to a non-ruq’ah font removes the effect of handwritten text and may remove the distinction between italic vs. regular styles in signage and other content using the FF Amman font in Jordan. The **_kano writing style_** is a common way of writing Hausa, especially in Northern Nigeria, in the ajami script, and like other West African writing it is based on Warsh (Warš) forms, which incorporate Maghribi characteristics. Text written in the Kano style will include glyphs for a number of African characters that may not be available in the average naskh font. See https://r12a.github.io/scripts/arabic/hausa#writing_styles Falling back to an arbitrary font will remove the identity of the content, and is likely to cause rendering failures for African characters. In fact, there is another orthography that looks much closer to naskh that is used with hand-written adaptations for the newspaper Al-Fijir, based on the Hafs orthography, but when writing in that orthography you need to use different code points from those used for the Kano style. So falling back to this would presumably lead to some confusion. The **_kufi writing style_** is the original style used for the Koran, but is not used for newspapers or official content today. However, it is used in modern content for logos and other stylised applications. See https://r12a.github.io/scripts/arabic/#sec_kufi_style Falling back to an arbitrary font would lose the decorative distinctions provided by the kufi font. This is, however, not quite the same as failing to render a Latin decorative font, since for Arabic this is a writing style, and there are likely to be other kufi style fonts on the system that would retain the decorative distinction intended. ## Syriac (Syriac, Assyrian Neo-Aramaic, Turoyo, …) Syriac has 3 major variant writing styles, Estrangelo, Serto (Western), and Madnhaya (Eastern). The code points for the consonant letters are the same, but the shapes of the letters and code points and shapes of vowel diacritics can vary significantly. Also, it is normal not to use code points for vowel diacritics in estrangelo text, whereas when writing the serto Turoyo language, or generally the madnhaya Assyrian dialects, the script has evolved into an alphabetic one that is fully vowelled. Noto provides separate fonts for each style, but my Mac falls back to the Noto Sans Syriac Eastern (the Madnhaya writing style), regardless of the language tags applied (syr, aii, tru, syr-Syrc, syr-Syrn, syr-Syre). (And by the way, the harmonisation of shapes in the Noto fonts neutralise much of the local flavour of these styles, if you compare with other fonts.) The **_estrangelo writing style_** is used in all ancient manuscripts. West and East Syriac text uses it for headers, titles, and subtitles. It's also the current standard for Western scholarship. See https://r12a.github.io/scripts/syriac/#writing_styles Falling back to a different writing style would reduce the distinctiveness of headings in languages that use East & West Syriac. For text in the Syriac language it would just look wrong. The **_serto writing style_** is used in West Syriac texts, the modern orthography for Turoyo, and Garshuni (Arabic written with Syriac). See https://r12a.github.io/scripts/syriac/#writing_styles Falling back to a different writing style would look wrong, especially for the Turoyo authors. The **_madnhaya writing style_** is used for modern East Syriac languages using Swadaya (Aramaic) texts, and in West Syriac texts for headers, titles and subtitles. See https://r12a.github.io/scripts/syriac/#writing_styles Falling back to a different writing style would reduce the distinctiveness of headings in languages that use West Syriac texts. For text in an Assyrian language it would just look wrong. ## Chinese Different writing styles tend to be applied to different bits of content in the same document to distinguish one feature of the content from another. Remember also that bolding, italicisation and underlining are not native traditions for Chinese, and so font choice is used to distinguish one type of text from another. This is actually a common technique in a number of scripts, not just Chinese. See https://w3c.github.io/clreq/#commonly_used_chinese_typefaces The **_song writing style_** is the most common typeface used in Chinese printing. Song is commonly used in text, headings and annotations. When used in headings, the characters will appear in a bold face, so as to distinguish the heading from the text. The **_kai writing style_** provides calligraphic styles for Chinese characters. It shows notable handwriting features. Kai is mainly used in text that needs to be differentiated from the rest of the content, for example, headlines, references, quotations, and dialogs. (It is rarely used for emphasis, because of its similarity to Song.) The **_hei writing style_**, also known as Gothic, is a type style characterized by strokes of even thickness, reduced curves, and a lack of decoration. It is commonly used in headlines, signs, and personal names in dialogs. In body text, characters in Hei style with thicker strokes typically indicate emphasis. Traditionally, publications rarely apply the Hei style for content, but with the growing influence of the World Wide Web and the digital publishing industry, some publications are starting to experiment Hei in this context. The **_fangsong writing style_** lies between Song and Kai. It is commonly used in secondary titles and isolated paragraphs such as quotations or highlighted sentences. Fallback to a single, arbitrary font is problematic because nullifies the distinctive characteristics of the text to which one of the above writing styles has been applied, for example removing emphasis. ## Tamil Tamil Nadu applied significant orthographic reforms in the latter part of the 20th century. But the orthographic reforms only spread in India and the digital world, whereas Sri Lanka, Singapore, Malaysia, Mauritius, Reunion and other Tamil speaking regions continue to use the traditional syllables. See https://r12a.github.io/scripts/tamil/#writing_styles Fallback to an arbitrary font may therefore change the regional identity of content and produce an unwelcome orthographic change. Malayalam also introduced orthographic simplifications in the late 20th century, though there may not be the same geographical split in usage as for Tamil. You can, however, find traditional vs modern fonts. I’m not aware that there are identity-related or practical issues for fallbacks to different fonts, though maybe this is a grey area. ## Khmer See https://r12a.github.io/scripts/khmer/#writing_styles The **_upright writing style_** is used for most modern typefaces (called អក្សរឈរ âksâr chôr). Fallback to an arbitrary font may not be a major issue, as long as it’s not the mul style, but would be equivalent in principle to blurring the distinction between serif and non-serif fonts in Latin script content. The **_slanted writing style_** (អក្សរជ្រៀង âksâr chriĕng) is used for whole documents or novels. The oblique styling has no effect on the semantics of the text. Fallback as above, i think. The **_round writing style_** (អក្សរមូល âksâr mul) includes more ligated forms, and is used for titles and headings in Cambodian documents, books, or currency, as well as on shop signs or banners. It may also be used to emphasise important names or nouns. Fallback to a font of another writing style (which is likely) would remove significant intentional differentiation in the text, including emphasis. Another style (អក្សរខម ʔk͓sṟkʰm̱), characterised by sharper serifs and angles and retainment of some antique characteristics, is used for yantra text in Cambodia as well as in Thailand. ## Northern Thai (Lanna) & Tai Kuhn Tai Tham script has 2 main orthographies. One is used for writing the Tai Khün language, and the other for writing the Lanna (or Northern Thai) language. The code points for the letters of each language are mostly, though not always, the same, but the shapes of certain letters vary systematically. (The one Noto font for Tai Tham generally favours glyph shapes associated with Tai Khün, but for some characters with significant differences it uses glyphs more similar to the typical Lanna style. Language tags have no effect.) The **_tai khün writing style_** is used for the Khün language. See https://r12a.github.io/scripts/taitham/#writing_styles Falling back to a different writing style would affect the identity of the text. The **_lanna writing style_** is used for the Northern Thai (Lanna) language. See https://r12a.github.io/scripts/taitham/#writing_styles Falling back to a different writing style would affect the identity of the text. ## Thai This is one may be a little more controversial, but essentially it boils down to the idea that glyphs in some Thai fonts have loops and in other fonts they don’t have loops. Loopless is considered to be more contemporary and modern, and is mainly used for advertising and titling. The distinction doesn’t necessarily map to that of serif vs sans – Noto, for example, provides both serif and sans Thai font faces, but they both have loops. On the other hand, Neue Frutiger Thai offers traditional (looped) and modern (loopless) alternatives as part of the same font family (each with both regular and italic substyles). There are, however, a large selection of looped fonts and a large selection of loopless, and it’s likely that replacing a looped font with an unlooped one, or vice versa, significantly changes the tone of the content. See http://www.fontpad.co.uk/loops-and-latinisation/#more-666 and https://r12a.github.io/scripts/thai/#writing_styles --- Coming up: my 2p about implementation: Yes that's a lot more generic styles than we currently have, and i'm sure there are more we would want. But those listed above are pretty standard and useful distinctions in relation to modern text, and as mentioned ignoring those distinctions can degrade the content in terms of identity or function. I also think we could start with the styles we know about and add more as needed. I'd like the generic fallback font system to move away from its current Western stylistic bias, to a more functional tool for dealing with the distinctions that are maintained in the many scripts around the world. I don't think its sensible to try to shoe-horn these needs into the current categories. I think we're looking at a registry of key writing styles, to which lists of fonts can be attached (either by the browser or the user, or both) in browser preferences. -- GitHub Notification of comment by r12a Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/4910#issuecomment-619342561 using your GitHub account
Received on Saturday, 25 April 2020 08:29:26 UTC