= Сообщение: 1373 из 2735 =================================== RU.FTN.DEVELOP = От : FGHI Robot 2:50/88 04 Apr 18 03:27:04 Кому : All 04 Apr 18 03:27:04 Тема : Fidonet runes (draft) FGHI : area://RU.FTN.DEVELOP?msgid=2:50/88+5ac41bdc = Кодировка сообщения определена как: ASCII ================================== ============================================================================== ********************************************************************** FGHI FIDONET GLOBAL HYPERTEXT INTERFACE ********************************************************************** Status: draft Revision: initial draft Title: Fidonet runes Author: Mithgol the Webmaster (aka Sergey Sokoloff, 2:50/88) Revision Date: 25 Mar 2018 -+-------------------------------------------------------------------- Contents: 1. Status of this document 2. Introduction 3. Key words to indicate requirement levels 4. Blank characters 5. Fidonet runes of images 6. Fidonet runes of hyperlinks 7. Runewords 7.1. Runewords of audio players 7.2. Runewords of video players 7.3. Runewords of video animation players 7.4. Runewords of panorama viewers Appendix A. Known implementations -+--------------------------------------------------------------------
1. Status of this document -+------------------------
This document is a draft of a Fidonet Standards Proposal (FSP).
This document specifies an optional Fidonet standard that can be used in the Fidonet community.
Implementation of the standard defined in this document is not mandatory, but all implementations are expected to adhere to this standard.
Distribution of this document is unlimited, provided that its text is not altered without notice.
2. Introduction -+-------------
Hypermedia elements (such as hyperlinks or images) have not been initially designed to appear in Fidonet messages: these messages have a textual nature.
This document specifies a lightweight markup that can be used for marking up some places in Fidonet messages where an element of hypermedia is necessary. Such markings are designed to be syntactically distinguishable from the text.
These elements of lightweight markup are called Fidonet runes.
Fidonet runes are not based on the systems that heavily utilize start tags and end tags (such as HTML or BBCode) because these do not have enough lightweightness in them.
Fidonet runes are based on their Markdown counterparts because that markup language (Markdown) is both lightweight and popular.
There are less Fidonet runes than Markdown markings. That's because some Markdown markings correspond to Fidonet features defined elsewhere (such as blockquotes, defined in FSC-0032) and also because some Fidonet runes are yet to be defined in the future versions of this document.
Some Fidonet runes differ from their Markdown counterparts (for example, permit and ignore an extra newline character) because Fidonet runes have to deal with limitations of its medium (Fidonet lines of text are 78 or 79 characters long traditionally, and IBM 80-column punched card format, designed in 1928, seems to be the historical cause for that).
3. Key words to indicate requirement levels -+-----------------------------------------
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in FTA-1006 (based on RFC 2119).
4. Blank characters -+-----------------
The following characters are blank characters:
*) horizontal tab (\t, Unicode U+0009),
*) line feed (\n, Unicode U+000A),
*) vertical tab (\v, Unicode U+000B),
*) form feed (\f, Unicode U+000C),
*) carriage return (\r, Unicode U+000D),
*) whitespace (Unicode U+0020),
*) no-break space (Unicode U+00A0),
*) Ogham space mark (Unicode U+1680),
*) Mongolian vowel separator (Unicode U+180E),
*) general punctuation spaces (Unicode from U+2000 to U+200A),
*) line separator (Unicode U+2028),
*) paragraph separator (Unicode U+2029),
*) narrow no-break space (Unicode U+202F),
*) medium mathematical space (Unicode U+205F),
*) ideographic space (Unicode U+3000),
*) zero width no-break space (Unicode U+FEFF).
They are used (as explained below) as separators in runes.
5. Fidonet runes of images -+------------------------
The Fidonet rune of an image has the following form:
where the words "alt text" (without quotes) are replaced by the alternative text (which is displayed instead of the image if that image itself cannot be displayed), and the word "URL" (without quotes) is replaced by the image's URL, and the word "title" (in quotes) is replaced by the image's title (which might be shown as a tooltip on a mouse's hover or a thumb's long press).
Initial and final newline characters in the alternative text MUST be ignored. Newline characters elsewhere in the alternative text MUST be treated as whitespaces. Therefore authors (and authoring tools) MAY insert newlines there to deal with limitations of the medium (Fidonet lines of text are 78 or 79 characters long traditionally, and IBM 80-column punched card format, designed in 1928, seems to be the historical cause for that).
The alternative text is enclosed in square brackets. Therefore, if such text itself contains a closing square bracket ("]" without quotes), such bracket MUST be preceded by a backslash in the rune (and "\]" without quotes MUST be interpreted as a literal "]" character and not as the alternative text's ending).
The image's title is OPTIONAL. When it is present, it MUST be separated (by one or more blank characters, see section 4) from the URL.
The image's title is enclosed in quotes. Double quotation marks ("like these") are used instead of single ('like these'). If the title itself contains a double quotation mark, such mark MUST be preceded by a backslash in the rune (and '\"' without single quotation marks MUST be interpreted as a literal '"' character and not as the title's ending).
The image's URL MUST NOT contain a closing parenthesis (the ")" character) because that would cause a premature end of the rune. Such parenthesis (if it appears in the URL) MUST be URL-encoded (presented as "%29" without quotes).
6. Fidonet runes of hyperlinks -+----------------------------
The Fidonet rune of a hyperlink has the following form:
[link text](URL "title")
where the words "link text" (without quotes) are replaced by the hyperlink's text, and the word "URL" (without quotes) is replaced by the hyperlink's URL, and the word "title" (in quotes) is replaced by the hyperlink's title (which might be shown as a tooltip on a mouse's hover or a thumb's long press).
Initial and final newline characters in the hyperlink's text MUST be ignored. Newline characters elsewhere in the hyperlink's text MUST be treated as whitespaces. Therefore authors (and authoring tools) MAY insert newlines there to deal with limitations of the medium (Fidonet lines of text are 78 or 79 characters long traditionally, and IBM 80-column punched card format, designed in 1928, seems to be the historical cause for that).
The hyperlink's text is enclosed in square brackets. Therefore, if such text itself contains a closing square bracket ("]" without quotes), such bracket MUST be preceded by a backslash in the rune (and "\]" without quotes MUST be interpreted as a literal "]" character and not as the hyperlink's text's ending).
As an exception to the aforementioned rule, the hyperlink's text MAY contain one or several Fidonet runes of images (see the previous section), and backslashes are not REQUIRED before the square brackets around the images' alternative texts.
The hyperlink's title is OPTIONAL. When it is present, it MUST be separated (by one or more blank characters, see section 4) from the URL.
The hyperlink's title is enclosed in quotes. Double quotation marks ("like these") are used instead of single ('like these'). If the title itself contains a double quotation mark, such mark MUST be preceded by a backslash in the rune (and '\"' without single quotation marks MUST be interpreted as a literal '"' character and not as the title's ending).
The hyperlink's URL MUST NOT contain a closing parenthesis (the ")" character) because that would cause a premature end of the rune. Such parenthesis (if it appears in the URL) MUST be URL-encoded (presented as "%29" without quotes).
If the hyperlink's title starts with a runeword (see the following section), then a more complex element of the hypertext SHOULD appear instead of the hyperlink.
7. Runewords -+----------
Runewords are keywords that MAY appear at the beginning of the title in a Fidonet rune of a hyperlink. Such a keyword indicates that Fidonet browsers SHOULD display a more complex object instead of a plain hyperlink there.
Runewords are somewhat forward compatible: if an unknown runeword is encountered or if a Fidonet browser decides to ignore the runeword, then a plain hyperlink MUST be displayed, serving as a fallback.
7.1. Runewords of audio players -+-----------------------------
If the title in a Fidonet rune of a hyperlink starts with the word "runeaudio" (without quotes and not case-sensitive), then Fidonet browsers SHOULD display an audio player instead of a plain hyperlink there.
The hyperlink's URL MUST be used as the audio's URL.
The hyperlink's title (except the starting runeword) MUST be used as the player's title (which might be shown as a tooltip on a mouse's hover or a thumb's long press).
If some Fidonet browsers can display the audio player and some cannot (for example, when Internet browsers are browsing a WebBBS that does not know if they support HTML5 audio tags), a fallback content MUST be provided for browsers that cannot display audio players.
(Such fallback content MUST at least contain the hyperlink's text, but it MAY contain the whole hyperlink, clickable and titled.)
An audio player MUST NOT autostart the audio.
An audio player MUST offer controls, allowing the user to control audio playback, including volume, seeking, pause/resume playback.
A Fidonet browser MAY decide not to display an audio player in some cases. For example,
*) when the hyperlink's URL scheme is not expected to address media files (such as "bitcoin:" or "geo:" or "sms:"),
*) when the hyperlink's URL scheme is not expected to address immediately available files (such as "faqserv:" or "magnet:"),
*) when the hyperlink's URL scheme uses an unavailable medium (such as "fecho:" on a system without file echomail archives).
In such cases a plain hyperlink MUST be displayed (ignoring the runeword).
Authors of Fidonet messages SHOULD use the audio format which is supported by most engines of browsers. That's MP3 in late 2017; it might be superseded by OPUS in the future.
7.2. Runewords of video players -+-----------------------------
If the title in a Fidonet rune of a hyperlink starts with the word "runevideo" (without quotes and not case-sensitive), then Fidonet browsers SHOULD display a video player instead of a plain hyperlink there.
The hyperlink's URL MUST be used as the video's URL.
The hyperlink's title (except the starting runeword) MUST be used as the player's title (which might be shown as a tooltip on a mouse's hover or a thumb's long press).
If some Fidonet browsers can display the video player and some cannot (for example, when Internet browsers are browsing a WebBBS that does not know if they support HTML5 video tags), a fallback content MUST be provided for browsers that cannot display video players.
(Such fallback content MUST at least contain the hyperlink's text, but it MAY contain the whole hyperlink, clickable and titled.)
A video player MUST NOT autostart the video.
A video player MUST offer controls, allowing the user to control video playback, including volume, seeking, pause/resume playback.
A Fidonet browser MAY decide not to display a video player in some cases. For example,
*) when the hyperlink's URL scheme is not expected to address media files (such as "bitcoin:" or "geo:" or "sms:"),
*) when the hyperlink's URL scheme is not expected to address immediately available files (such as "faqserv:" or "magnet:"),
*) when the hyperlink's URL scheme uses an unavailable medium (such as "fecho:" on a system without file echomail archives).
In such cases a plain hyperlink MUST be displayed (ignoring the runeword).
In late 2017 authors of Fidonet messages are unable to choose a universally acceptable video format. For example, .MP4 files (MPEG-4/H.264) are not supported in Chromium, and WebM files are not supported in iOS (on iPhones and iPads). In terms of quality newer WebM files (using VP9 video codec and Opus audio) are usually superior. In the future AV1 video codec (AOMedia Video 1) is likely to prevail.
7.3. Runewords of video animation players -+---------------------------------------
If the title in a Fidonet rune of a hyperlink starts with the word "runeanim" (without quotes and not case-sensitive), then Fidonet browsers SHOULD display a video animation player instead of a plain hyperlink there.
The hyperlink's URL MUST be used as the video's URL.
The hyperlink's title (except the starting runeword) MUST be used as the player's title (which might be shown as a tooltip on a mouse's hover or a thumb's long press).
If some Fidonet browsers can display the video player and some cannot (for example, when Internet browsers are browsing a WebBBS that does not know if they support HTML5 video tags), a fallback content MUST be provided for browsers that cannot display video players.
(Such fallback content MUST at least contain the hyperlink's text, but it MAY contain the whole hyperlink, clickable and titled.)
A video animation player MUST autostart the video.
The audio contained in the video MUST be initially silenced. (The viewer MAY unmute the video later using its controls, mentioned below.)
A video animation player MUST, upon reaching the end of the video, automatically seek back to the start and continue playing.
A video animation player MUST offer controls, allowing the user to control video playback, including volume, seeking, pause/resume playback.
A Fidonet browser MAY decide not to display a video animation player in some cases. For example,
*) when the hyperlink's URL scheme is not expected to address media files (such as "bitcoin:" or "geo:" or "sms:"),
*) when the hyperlink's URL scheme is not expected to address immediately available files (such as "faqserv:" or "magnet:"),
*) when the hyperlink's URL scheme uses an unavailable medium (such as "fecho:" on a system without file echomail archives).
In such cases a plain hyperlink MUST be displayed (ignoring the runeword).
In late 2017 authors of Fidonet messages are unable to choose a universally acceptable video format. For example, .MP4 files (MPEG-4/H.264) are not supported in Chromium, and WebM files are not supported in iOS (on iPhones and iPads). In terms of quality newer WebM files (using VP9 video codec and Opus audio) are usually superior. In the future AV1 video codec (AOMedia Video 1) is likely to prevail.
Video animation players (in this section) are designed almost like regular video players (in the previous section) but they have the following three differences:
1) they autostart,
2) they loop (automatically seek back to the start),
3) they are silent.
These differences allow video animation players to be suitable replacements for animated GIF images (which also are silent and also autostart and loop animations). The desired improvement is that video files are generally smaller (filesize-wise) than animated GIFs and they also provide more colors and thus better quality of their frames.
7.4. Runewords of panorama viewers -+--------------------------------
If the title in a Fidonet rune of a hyperlink starts with the word "runepano" (without quotes and not case-sensitive), then Fidonet browsers SHOULD display a panorama viewer instead of a plain hyperlink there.
The hyperlink's URL MUST be used as the panorama's URL. The URL is REQUIRED to designate an image file containing a panoramic photo in the equirectangular projection.
The hyperlink's title (except the starting runeword) MUST be used as the viewer's title (which might be shown as a tooltip on a mouse's hover or a thumb's long press, might be displayed in a semi-transparent block over the viewer, etc.).
If some Fidonet browsers can display the panorama viewer and some cannot (for example, when Internet browsers are browsing a WebBBS that does not know if they support a WebGL-based viewer used by that WebBBS), a fallback content SHOULD be provided for browsers that cannot display panorama viewers.
(Such fallback content MUST at least contain the hyperlink's text, but it MAY contain the whole hyperlink, clickable and titled.)
A panorama viewer MAY demonstrate its nature by autostarting the panoramic photo's rotation slowly (a degree per second).
A panorama viewer MUST offer controls, allowing the user to rotate the panorama by dragging. (It SHOULD also rotate when the user rotates the mobile device, if the viewer is run on such device.)
A Fidonet browser MAY decide not to display a panorama viewer in some cases. For example,
*) when the hyperlink's URL scheme is not expected to address image files (such as "bitcoin:" or "geo:" or "sms:"),
*) when the hyperlink's URL scheme is not expected to address immediately available files (such as "faqserv:" or "magnet:"),
*) when the hyperlink's URL scheme uses an unavailable medium (such as "fecho:" on a system without file echomail archives),
*) when the hyperlink's URL scheme cannot be used by the viewer (such as "ftp:" that cannot provide CORS to WebGL-based viewers using image files as WebGL textures).
In such cases a plain hyperlink MUST be displayed (ignoring the runeword).
Authors of Fidonet messages SHOULD use the image format and host appropriate for most viewer engines and browsers. For example,
*) JPEG has wider support than WebP in 2018,
*) if Cross-Origin Resource Sharing (CORS) is not enabled on a host, then WebGL-based viewers will fail (because they won't be able to use the image as a texture) and also canvas-based viewers will fail (because they won't be able to use the image in drawImage),
*) HTTP-served images trigger warnings (or become blocked; it depends on the browser's settings) in HTTPS-served viewers,
*) panorama viewers that use hardware acceleration might fail when the image is wider than 8192 pixels (and even when it's wider than 4096 pixels on older devices), and some GPU are rumoured to struggle with large textures even if they technically support them.
Appendix A. Known implementations -+-------------------------------
By the time of this writing there are several implementation of the draft editions of this standard.
********************************************************************** EOTD END OF THE DOCUMENT ********************************************************************** --- Mithgol's NodePost * Origin: Make Fidonet great again (2:50/88)
