macOS 14.7.2 iMac27inch
Illustrator ver.29.3.1

再現手順
1. 新規ドキュメントを開きアートボード上に「Air」と入力し欧文フォント（スワッシュ字形が有効なもの）を指定する。
2.OpenTypeパネルの「スワッシュ字形」と「タイトル用字形」をクリックする。
3.SVG形式で保存。その際、フォントをサブセットで埋め込む。
4.ブラウザ等で確認するとスワッシュ字形等がデフォルトの字形で表示される。

期待する結果
スワッシュ字形やタイトル用字形が正しく表示される。

実際の結果
スワッシュ字形やタイトル用字形が標準字形になる。

SwashやTitlingAlternatesはスタイルに対してfont-feature-settings等の設定が必要になりますが、Illustratorはそういった設定を保存しません。また、フォントサブセットを保存した場合でも標準字形のグリフが保存されます。

EN Translate:
Step to Reproduce
1. open a new document, type "Air" on the artboard, and specify a western font (with swash glyphs enabled).
2. Click "Swash" and "Titling Alternates" in the OpenType panel.
3. Save the file in SVG format. (Embed the font as a subset.)
4. When we check the file in a browser, the swash and Titling Alternates will be displayed as default glyph.

Expected Results
Swash and titlling Alternates are displayed correctly.

Actual result
Swash and titleling Altermates are fallback to defalt glyph.

Swash and TitlingAlternates require font-feature-settings and other settings for styles, but Illustrator does not save such settings. Also, when font subsets are saved, the glyphs of the default glyphs are saved.

Please delete the ".pdf" extension from the attached pdf file and open it in Illustrator.

The SVG that Illustrator saves is shown below.

<?xml version="1.0" encoding="utf-8"?>
<!-- Generator: Adobe Illustrator 29.3.1, SVG Export Plug-In . SVG Version: 9.03 Build 55982) -->
<svg version="1.1" id="layer1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"
viewBox="0 0 111 111" style="enable-background:new 0 0 111 111;" xml:space="preserve">
<style type="text/css">
.st0{fill:#231815;}
.st1{font-family:'Atocha';}
.st2{font-size:12px;}
</style>
<font horiz-adv-x="1000">
<!-- Copyright (c) 2016 by Jose Luis Vivas and Alejandro Paul. All rights reserved. www.sudtipos.com, with Reserved Font Name "Atocha" -->
<!-- Copyright: Copyright 2025 Adobe System Incorporated. All rights reserved. -->
<font-face font-family="Atocha" units-per-em="1000" underline-position="-100" underline-thickness="50"/>
<missing-glyph horiz-adv-x="180"/>
<glyph unicode="A" horiz-adv-x="650" d="M-8,474C-23,474 -41,433 -41,359C-41,303 -12,208 131,184C110,78 97,-29 97,-128C97,-195 151,-243 203,-243C216,-243 221,-233 221,-222C221,-205 197,-121 197,-30C197,39 203,110 215,178C281,179 376,194 454,212C454,185 455,160 455,137C455,62 452,9 448,5C445,2 443,-1 443,-5C443,-28 503,-56 545,-56C559,-56 571,-53 578,-46C581,-42 583,-20 583,16C583,69 579,152 569,244C589,252 621,270 621,293C621,302 608,328 589,328C585,328 575,325 560,322C537,507 493,707 422,778C414,786 406,789 398,789C374,789 353,759 348,734C286,680 206,495 153,284C33,316 -8,397 -8,422C-8,445 2,460 2,468C2,472 -1,474 -8,474M258,272l-25,0C277,468 349,629 374,676C421,599 442,439 450,295C392,283 323,272 258,272z"/>
<glyph unicode="i" horiz-adv-x="192" d="M239,117C250,154 252,188 252,201C252,213 234,221 223,221C218,221 214,219 214,216C209,178 194,75 137,75C125,75 121,108 121,152C121,243 138,383 138,383C138,383 145,387 145,401C145,421 140,433 131,442C117,456 94,465 75,465C65,465 55,462 48,456C33,442 21,341 21,243C21,158 30,75 53,52C81,24 120,4 136,4C179,4 221,56 239,117M69,651C69,603 109,576 128,576C172,576 177,643 192,658C195,661 198,666 198,672C198,704 178,731 143,731C128,731 98,720 86,708C74,696 69,684 69,651z"/>
<glyph unicode="r" horiz-adv-x="314" d="M248,-16C345,-16 372,143 377,216l0,2C377,238 360,258 349,258C344,258 341,255 340,246C338,224 318,29 258,29C245,29 235,47 235,97C235,151 256,335 256,369C256,416 142,451 79,474l0,30C79,524 61,532 41,532C15,532 -15,518 -15,498C-15,478 8,464 38,452C36,305 23,216 23,216l0,-2C23,202 44,192 56,190C61,190 61,194 61,194C61,194 74,294 78,436C114,422 148,407 148,385C148,359 128,229 128,149C128,70 147,-16 248,-16z"/>
</font>
<text transform="matrix(1 0 0 1 46.1946 58.2838)" class="st0 st1 st2">Air</text>
</svg>

In contrast, the following is the one adjusted so that the browser can normally display Swash, etc.

<?xml version="1.0" encoding="utf-8"?>
<!-- Generator: Adobe Illustrator 29.3.1, SVG Export Plug-In . SVG Version: 9.03 Build 55982) -->
<svg version="1.1" id="layer1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"
viewBox="0 0 111 111" style="enable-background:new 0 0 111 111;" xml:space="preserve">
<style type="text/css">
.st0{fill:#231815;}
</style>
<font horiz-adv-x="1000">
<font-face font-family="Atocha" units-per-em="1000" underline-position="-100" underline-thickness="50"/>
</font>
<text transform="matrix(1 0 0 1 46.1946 58.2838)" class="st0"
style="font-family:'Atocha'; font-size:12px;
font-feature-settings: 'swsh' 1, 'titl' 1;
font-variant-alternates: titling-caps;
letter-spacing: 0;
text-rendering: optimizeLegibility;">
Air</text>
</svg>