Did you know Unicode has italic letters? And bold. And sans-serif-italic-bold. And Fraktur, whatever that is. Also, did you know that on some forums, you can combine both Unicode and markdown/BBCode/etc. italics, for doubly-slanty words? This short blob of JavaScript can be dumped into any browser console and to assist in text decoration shenani…

italicize.js

/* Letter variants collected from https://en.wikipedia.org/wiki/Mathematical_Alphanumeric_Symbols_(Unicode_block) */
let alphabets = {
    plain: 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789'.split(''),
    sans: '𝖠 𝖡 𝖢 𝖣 𝖤 𝖥 𝖦 𝖧 𝖨 𝖩 𝖪 𝖫 𝖬 𝖭 𝖮 𝖯 𝖰 𝖱 𝖲 𝖳 𝖴 𝖵 𝖶 𝖷 𝖸 𝖹 𝖺 𝖻 𝖼 𝖽 𝖾 𝖿 𝗀 𝗁 𝗂 𝗃 𝗄 𝗅 𝗆 𝗇 𝗈 𝗉 𝗊 𝗋 𝗌 𝗍 𝗎 𝗏 𝗐 𝗑 𝗒 𝗓 𝟢 𝟣 𝟤 𝟥 𝟦 𝟧 𝟨 𝟩 𝟪 𝟫'.split(' '),
    serif_italic: '𝐴 𝐵 𝐶 𝐷 𝐸 𝐹 𝐺 𝐻 𝐼 𝐽 𝐾 𝐿 𝑀 𝑁 𝑂 𝑃 𝑄 𝑅 𝑆 𝑇 𝑈 𝑉 𝑊 𝑋 𝑌 𝑍 𝑎 𝑏 𝑐 𝑑 𝑒 𝑓 𝑔 ℎ 𝑖 𝑗 𝑘 𝑙 𝑚 𝑛 𝑜 𝑝 𝑞 𝑟 𝑠 𝑡 𝑢 𝑣 𝑤 𝑥 𝑦 𝑧 0 1 2 3 4 5 6 7 8 9'.split(' '),
    sans_italic: '𝘈 𝘉 𝘊 𝘋 𝘌 𝘍 𝘎 𝘏 𝘐 𝘑 𝘒 𝘓 𝘔 𝘕 𝘖 𝘗 𝘘 𝘙 𝘚 𝘛 𝘜 𝘝 𝘞 𝘟 𝘠 𝘡 𝘢 𝘣 𝘤 𝘥 𝘦 𝘧 𝘨 𝘩 𝘪 𝘫 𝘬 𝘭 𝘮 𝘯 𝘰 𝘱 𝘲 𝘳 𝘴 𝘵 𝘶 𝘷 𝘸 𝘹 𝘺 𝘻 0 1 2 3 4 5 6 7 8 9'.split(' '),
    serif_bold: '𝐀 𝐁 𝐂 𝐃 𝐄 𝐅 𝐆 𝐇 𝐈 𝐉 𝐊 𝐋 𝐌 𝐍 𝐎 𝐏 𝐐 𝐑 𝐒 𝐓 𝐔 𝐕 𝐖 𝐗 𝐘 𝐙 𝐚 𝐛 𝐜 𝐝 𝐞 𝐟 𝐠 𝐡 𝐢 𝐣 𝐤 𝐥 𝐦 𝐧 𝐨 𝐩 𝐪 𝐫 𝐬 𝐭 𝐮 𝐯 𝐰 𝐱 𝐲 𝐳 𝟎 𝟏 𝟐 𝟑 𝟒 𝟓 𝟔 𝟕 𝟖 𝟗'.split(' '),
    sans_bold: '𝗔 𝗕 𝗖 𝗗 𝗘 𝗙 𝗚 𝗛 𝗜 𝗝 𝗞 𝗟 𝗠 𝗡 𝗢 𝗣 𝗤 𝗥 𝗦 𝗧 𝗨 𝗩 𝗪 𝗫 𝗬 𝗭 𝗮 𝗯 𝗰 𝗱 𝗲 𝗳 𝗴 𝗵 𝗶 𝗷 𝗸 𝗹 𝗺 𝗻 𝗼 𝗽 𝗾 𝗿 𝘀 𝘁 𝘂 𝘃 𝘄 𝘅 𝘆 𝘇 𝟬 𝟭 𝟮 𝟯 𝟰 𝟱 𝟲 𝟳 𝟴 𝟵'.split(' '),
    serif_bold_italic: '𝑨 𝑩 𝑪 𝑫 𝑬 𝑭 𝑮 𝑯 𝑰 𝑱 𝑲 𝑳 𝑴 𝑵 𝑶 𝑷 𝑸 𝑹 𝑺 𝑻 𝑼 𝑽 𝑾 𝑿 𝒀 𝒁 𝒂 𝒃 𝒄 𝒅 𝒆 𝒇 𝒈 𝒉 𝒊 𝒋 𝒌 𝒍 𝒎 𝒏 𝒐 𝒑 𝒒 𝒓 𝒔 𝒕 𝒖 𝒗 𝒘 𝒙 𝒚 𝒛 0 1 2 3 4 5 6 7 8 9'.split(' '),
    sans_bold_italic: '𝘼 𝘽 𝘾 𝘿 𝙀 𝙁 𝙂 𝙃 𝙄 𝙅 𝙆 𝙇 𝙈 𝙉 𝙊 𝙋 𝙌 𝙍 𝙎 𝙏 𝙐 𝙑 𝙒 𝙓 𝙔 𝙕 𝙖 𝙗 𝙘 𝙙 𝙚 𝙛 𝙜 𝙝 𝙞 𝙟 𝙠 𝙡 𝙢 𝙣 𝙤 𝙥 𝙦 𝙧 𝙨 𝙩 𝙪 𝙫 𝙬 𝙭 𝙮 𝙯 0 1 2 3 4 5 6 7 8 9'.split(' '),
    script: '𝒜 ℬ 𝒞 𝒟 ℰ ℱ 𝒢 ℋ ℐ 𝒥 𝒦 ℒ ℳ 𝒩 𝒪 𝒫 𝒬 ℛ 𝒮 𝒯 𝒰 𝒱 𝒲 𝒳 𝒴 𝒵 𝒶 𝒷 𝒸 𝒹 ℯ 𝒻 ℊ 𝒽 𝒾 𝒿 𝓀 𝓁 𝓂 𝓃 ℴ 𝓅 𝓆 𝓇 𝓈 𝓉 𝓊 𝓋 𝓌 𝓍 𝓎 𝓏 0 1 2 3 4 5 6 7 8 9'.split(' '),
    script_bold: '𝓐 𝓑 𝓒 𝓓 𝓔 𝓕 𝓖 𝓗 𝓘 𝓙 𝓚 𝓛 𝓜 𝓝 𝓞 𝓟 𝓠 𝓡 𝓢 𝓣 𝓤 𝓥 𝓦 𝓧 𝓨 𝓩 𝓪 𝓫 𝓬 𝓭 𝓮 𝓯 𝓰 𝓱 𝓲 𝓳 𝓴 𝓵 𝓶 𝓷 𝓸 𝓹 𝓺 𝓻 𝓼 𝓽 𝓾 𝓿 𝔀 𝔁 𝔂 𝔃 0 1 2 3 4 5 6 7 8 9'.split(' '),
    fraktur: '𝔄 𝔅 ℭ 𝔇 𝔈 𝔉 𝔊 ℌ ℑ 𝔍 𝔎 𝔏 𝔐 𝔑 𝔒 𝔓 𝔔 ℜ 𝔖 𝔗 𝔘 𝔙 𝔚 𝔛 𝔜 ℨ 𝔞 𝔟 𝔠 𝔡 𝔢 𝔣 𝔤 𝔥 𝔦 𝔧 𝔨 𝔩 𝔪 𝔫 𝔬 𝔭 𝔮 𝔯 𝔰 𝔱 𝔲 𝔳 𝔴 𝔵 𝔶 𝔷 0 1 2 3 4 5 6 7 8 9'.split(' '),
    fraktur_bold: '𝕬 𝕭 𝕮 𝕯 𝕰 𝕱 𝕲 𝕳 𝕴 𝕵 𝕶 𝕷 𝕸 𝕹 𝕺 𝕻 𝕼 𝕽 𝕾 𝕿 𝖀 𝖁 𝖂 𝖃 𝖄 𝖅 𝖆 𝖇 𝖈 𝖉 𝖊 𝖋 𝖌 𝖍 𝖎 𝖏 𝖐 𝖑 𝖒 𝖓 𝖔 𝖕 𝖖 𝖗 𝖘 𝖙 𝖚 𝖛 𝖜 𝖝 𝖞 𝖟 0 1 2 3 4 5 6 7 8 9'.split(' '),
    monospace: '𝙰 𝙱 𝙲 𝙳 𝙴 𝙵 𝙶 𝙷 𝙸 𝙹 𝙺 𝙻 𝙼 𝙽 𝙾 𝙿 𝚀 𝚁 𝚂 𝚃 𝚄 𝚅 𝚆 𝚇 𝚈 𝚉 𝚊 𝚋 𝚌 𝚍 𝚎 𝚏 𝚐 𝚑 𝚒 𝚓 𝚔 𝚕 𝚖 𝚗 𝚘 𝚙 𝚚 𝚛 𝚜 𝚝 𝚞 𝚟 𝚠 𝚡 𝚢 𝚣 𝟶 𝟷 𝟸 𝟹 𝟺 𝟻 𝟼 𝟽 𝟾 𝟿'.split(' '),
    double_struck: '𝔸 𝔹 ℂ 𝔻 𝔼 𝔽 𝔾 ℍ 𝕀 𝕁 𝕂 𝕃 𝕄 ℕ 𝕆 ℙ ℚ ℝ 𝕊 𝕋 𝕌 𝕍 𝕎 𝕏 𝕐 ℤ 𝕒 𝕓 𝕔 𝕕 𝕖 𝕗 𝕘 𝕙 𝕚 𝕛 𝕜 𝕝 𝕞 𝕟 𝕠 𝕡 𝕢 𝕣 𝕤 𝕥 𝕦 𝕧 𝕨 𝕩 𝕪 𝕫 𝟘 𝟙 𝟚 𝟛 𝟜 𝟝 𝟞 𝟟 𝟠 𝟡'.split(' '),
    superscript: 'ᴬ ᴮ C ᴰ ᴱ F ᴳ ᴴ ᴵ ᴶ ᴷ ᴸ ᴹ ᴺ ᴼ ᴾ Q ᴿ S ᵀ ᵁ ⱽ ᵂ X Y Z ᵃ ᵇ ᶜ ᵈ ᵉ ᶠ ᵍ ʰ ⁱ ʲ ᵏ ˡ ᵐ ⁿ ᵒ ᵖ q ʳ ˢ ᵗ ᵘ ᵛ ʷ ˣ ʸ ᶻ ⁰ ¹ ² ³ ⁴ ⁵ ⁶ ⁷ ⁸ ⁹'.split(' '),
    subscript: 'A B C D E F G H I J K L M N O P Q R S T U V W X Y Z ₐ b c d ₑ f g ₕ ᵢ ⱼ ₖ ₗ ₘ ₙ ₒ ₚ q ᵣ ₛ ₜ ᵤ ᵥ w ₓ y z ₀ ₁ ₂ ₃ ₄ ₅ ₆ ₇ ₈ ₉'.split(' '),
    small_caps: 'ᴀ ʙ ᴄ ᴅ ᴇ ꜰ ɢ ʜ ɪ ᴊ ᴋ ʟ ᴍ ɴ ᴏ ᴘ ꞯ ʀ ꜱ ᴛ ᴜ ᴠ ᴡ X ʏ ᴢ a b c d e f g h i j k l m n o p q r s t u v w x y z 0 1 2 3 4 5 6 7 8 9'
}

function map_alphabets(text, from, to) {
    let result = '';
    for(let ch of text) {
        let idx = from.indexOf(ch);
        result += idx < 0? ch : to[idx];
    }
    return result;
}

function italicize(text, serif) {
    return map_alphabets(text, alphabets.plain, serif? alphabets.serif_italic : alphabets.sans_italic);
}