diff --git a/examples/tsconfig.json b/examples/tsconfig.json
index 78d9d703..192a09bb 100644
--- a/examples/tsconfig.json
+++ b/examples/tsconfig.json
@@ -1,5 +1,5 @@
 {
     "compilerOptions": { "rootDir": "./" },
     "include": ["./**/*.ts"],
-    "extends": "../tsconfig.build.json",
+    "extends": "../tsconfig.build.json"
 }
diff --git a/package.json b/package.json
index cd0874bd..ad70b754 100644
--- a/package.json
+++ b/package.json
@@ -19,7 +19,7 @@
         "test:packages-esm": "cd test/esm && npm install && npm run test",
         "test:packages-cjs": "cd test/cjs && npm install && npm run test",
         "test:packages-install": "cd test && npx vite-node make-packages.ts",
-        "prettier": "prettier \"**/*.ts\" \"**/*.json\" --write",
+        "prettier": "prettier \"**/*.ts\" \"**/*.json\" --ignore-path .gitignore --write",
         "eslint": "eslint \"**/*.ts\" --ignore-pattern dist"
     },
     "prettier": {
diff --git a/packages/unified-latex-types/index.ts b/packages/unified-latex-types/index.ts
index e3985eec..381f8745 100644
--- a/packages/unified-latex-types/index.ts
+++ b/packages/unified-latex-types/index.ts
@@ -2,6 +2,9 @@ export * from "./libs/ast-types";
 export * from "./libs/type-guard";
 export * from "./libs/info-specs";
 
+// Export something for importing packages
+export default {};
+
 // NOTE: The docstring comment must be the last item in the index.ts file!
 /**
  * ## What is this?
diff --git a/packages/unified-latex-types/libs/ast-types.ts b/packages/unified-latex-types/libs/ast-types.ts
index a9757048..a7a34070 100644
--- a/packages/unified-latex-types/libs/ast-types.ts
+++ b/packages/unified-latex-types/libs/ast-types.ts
@@ -11,8 +11,9 @@ export interface GenericNode {
 // Abstract nodes
 interface BaseNode {
     type: string;
-    _renderInfo?: (MacroInfo["renderInfo"] | EnvInfo["renderInfo"]) &
-        Record<string, unknown>;
+    _renderInfo?: (MacroInfo["renderInfo"] | EnvInfo["renderInfo"]) & {
+        defaultArg?: string;
+    } & Record<string, unknown>;
     position?: {
         start: { offset: number; line: number; column: number };
         end: { offset: number; line: number; column: number };
diff --git a/packages/unified-latex-types/package.json b/packages/unified-latex-types/package.json
index a5999c86..014db447 100644
--- a/packages/unified-latex-types/package.json
+++ b/packages/unified-latex-types/package.json
@@ -13,12 +13,14 @@
     "exports": {
         ".": {
             "prebuilt": "./dist/index.js",
-            "import": "./index.ts"
+            "import": "./index.ts",
+            "require": "./dist/index.cjs"
         },
         "./*js": "./dist/*js",
         "./*": {
             "prebuilt": "./dist/*.js",
-            "import": "./*.ts"
+            "import": "./*.ts",
+            "require": "./dist/*.cjs"
         }
     },
     "scripts": {
diff --git a/packages/unified-latex-util-argspec/libs/argspec-parser.ts b/packages/unified-latex-util-argspec/libs/argspec-parser.ts
index 8c3015c1..aed449d3 100644
--- a/packages/unified-latex-util-argspec/libs/argspec-parser.ts
+++ b/packages/unified-latex-util-argspec/libs/argspec-parser.ts
@@ -31,9 +31,11 @@ export function printRaw(
     }
 
     const decorators = getDecorators(node);
-    const defaultArg = (node as ArgSpec.DefaultArgument).defaultArg
-        ? printRaw((node as ArgSpec.DefaultArgument).defaultArg!)
-        : "";
+    const defaultArg = printDefaultArg(
+        "defaultArg" in node ? node.defaultArg : undefined,
+        // `embellishment`s are the only spec that can have multiple default args
+        node.type === "embellishment"
+    );
     let spec = decorators;
 
     const type = node.type;
@@ -101,3 +103,19 @@ export function parse(str = ""): ArgSpec.Node[] {
     parseCache[str] = parseCache[str] || PegParser.parse(str);
     return parseCache[str];
 }
+
+function printDefaultArg(
+    args: string | string[] | undefined,
+    multipleArgs: boolean
+): string {
+    if (!args) {
+        return "";
+    }
+    if (typeof args === "string") {
+        args = [args];
+    }
+    if (!multipleArgs) {
+        return `{${args.join("")}}`;
+    }
+    return `{${args.map((a) => `{${a}}`).join("")}}`;
+}
diff --git a/packages/unified-latex-util-argspec/libs/argspec-types.ts b/packages/unified-latex-util-argspec/libs/argspec-types.ts
index a6dfca7c..0be0549b 100644
--- a/packages/unified-latex-util-argspec/libs/argspec-types.ts
+++ b/packages/unified-latex-util-argspec/libs/argspec-types.ts
@@ -12,7 +12,10 @@ export interface LeadingWhitespace {
     noLeadingWhitespace: boolean | undefined;
 }
 export interface DefaultArgument {
-    defaultArg?: Group;
+    defaultArg?: string;
+}
+export interface DefaultArguments {
+    defaultArg?: string[];
 }
 interface Verbatim extends Arg {
     type: "verbatim";
@@ -27,7 +30,7 @@ interface OptionalToken extends LeadingWhitespace, AstNode {
     type: "optionalToken";
     token: string;
 }
-export interface Embellishment extends DefaultArgument, AstNode {
+export interface Embellishment extends DefaultArguments, AstNode {
     type: "embellishment";
     embellishmentTokens: string[];
 }
diff --git a/packages/unified-latex-util-argspec/tests/__snapshots__/argspec-parser.test.ts.snap b/packages/unified-latex-util-argspec/tests/__snapshots__/argspec-parser.test.ts.snap
index c0568d13..e95580fc 100644
--- a/packages/unified-latex-util-argspec/tests/__snapshots__/argspec-parser.test.ts.snap
+++ b/packages/unified-latex-util-argspec/tests/__snapshots__/argspec-parser.test.ts.snap
@@ -27,30 +27,7 @@ exports[`unified-latex-util-argspec > parses xparse argument specification strin
 [
   {
     "closeBrace": "]",
-    "defaultArg": {
-      "content": [
-        "n",
-        "e",
-        "s",
-        "t",
-        "e",
-        "d",
-        {
-          "content": [
-            "d",
-            "e",
-            "f",
-            "a",
-            "u",
-            "l",
-            "t",
-            "s",
-          ],
-          "type": "group",
-        },
-      ],
-      "type": "group",
-    },
+    "defaultArg": "nested{defaults}",
     "openBrace": "[",
     "type": "optional",
   },
@@ -61,22 +38,7 @@ exports[`unified-latex-util-argspec > parses xparse argument specification strin
 [
   {
     "closeBrace": "]",
-    "defaultArg": {
-      "content": [
-        "s",
-        "o",
-        "m",
-        "e",
-        "d",
-        "e",
-        "f",
-        "a",
-        "u",
-        "l",
-        "t",
-      ],
-      "type": "group",
-    },
+    "defaultArg": "somedefault",
     "openBrace": "[",
     "type": "optional",
   },
@@ -93,6 +55,17 @@ exports[`unified-latex-util-argspec > parses xparse argument specification strin
 ]
 `;
 
+exports[`unified-latex-util-argspec > parses xparse argument specification string "R\\a1{default}" 1`] = `
+[
+  {
+    "closeBrace": "1",
+    "defaultArg": "default",
+    "openBrace": "\\\\a",
+    "type": "mandatory",
+  },
+]
+`;
+
 exports[`unified-latex-util-argspec > parses xparse argument specification string "d++ D--{def}" 1`] = `
 [
   {
@@ -102,14 +75,7 @@ exports[`unified-latex-util-argspec > parses xparse argument specification strin
   },
   {
     "closeBrace": "-",
-    "defaultArg": {
-      "content": [
-        "d",
-        "e",
-        "f",
-      ],
-      "type": "group",
-    },
+    "defaultArg": "def",
     "openBrace": "-",
     "type": "optional",
   },
@@ -219,6 +185,16 @@ exports[`unified-latex-util-argspec > parses xparse argument specification strin
 ]
 `;
 
+exports[`unified-latex-util-argspec > parses xparse argument specification string "r\\abc\\d" 1`] = `
+[
+  {
+    "closeBrace": "\\\\d",
+    "openBrace": "\\\\abc",
+    "type": "mandatory",
+  },
+]
+`;
+
 exports[`unified-latex-util-argspec > parses xparse argument specification string "s m" 1`] = `
 [
   {
diff --git a/packages/unified-latex-util-argspec/tests/argspec-parser.test.ts b/packages/unified-latex-util-argspec/tests/argspec-parser.test.ts
index f4e49953..7d02b666 100644
--- a/packages/unified-latex-util-argspec/tests/argspec-parser.test.ts
+++ b/packages/unified-latex-util-argspec/tests/argspec-parser.test.ts
@@ -1,7 +1,7 @@
 import { describe, it, expect } from "vitest";
 import { VFile } from "unified-lint-rule/lib";
 import util from "util";
-import * as argspecParser from "..";
+import * as argspecParser from "../index";
 
 /* eslint-env jest */
 
@@ -18,6 +18,7 @@ function removeWhitespace(x: string) {
 describe("unified-latex-util-argspec", () => {
     let value: string | undefined;
     let file: VFile | undefined;
+    let ast: ReturnType<typeof argspecParser.parse>;
 
     const SPEC_STRINGS = [
         "",
@@ -35,6 +36,8 @@ describe("unified-latex-util-argspec", () => {
         "u{xx;}",
         "u;",
         "u{ }",
+        "r\\abc\\d",
+        "R\\a1{default}",
     ];
 
     for (const spec of SPEC_STRINGS) {
@@ -45,17 +48,98 @@ describe("unified-latex-util-argspec", () => {
         });
     }
 
+    it("Default args need not be enclosed in braces", () => {
+        ast = argspecParser.parse("Ox");
+        expect(ast).toEqual([
+            {
+                closeBrace: "]",
+                defaultArg: "x",
+                openBrace: "[",
+                type: "optional",
+            },
+        ]);
+
+        ast = argspecParser.parse("D(ab");
+        expect(ast).toEqual([
+            {
+                closeBrace: "a",
+                defaultArg: "b",
+                openBrace: "(",
+                type: "optional",
+            },
+        ]);
+    });
+
+    it("Embellishment tokens can be single characters specified without a group", () => {
+        ast = argspecParser.parse("e^");
+        expect(ast).toEqual([
+            {
+                type: "embellishment",
+                embellishmentTokens: ["^"],
+            },
+        ]);
+
+        // Macros count as a single token
+        ast = argspecParser.parse("e\\foo");
+        expect(ast).toEqual([
+            {
+                type: "embellishment",
+                embellishmentTokens: ["\\foo"],
+            },
+        ]);
+
+        ast = argspecParser.parse("Ex{}");
+        expect(ast).toEqual([
+            {
+                type: "embellishment",
+                embellishmentTokens: ["x"],
+                defaultArg: [],
+            },
+        ]);
+    });
+
+    it("Embellishment tokens ignore whitespace", () => {
+        ast = argspecParser.parse("e { ^ }");
+        expect(ast).toEqual([
+            {
+                type: "embellishment",
+                embellishmentTokens: ["^"],
+            },
+        ]);
+    });
+
+    it("Embellishment default args can be a mix of tokens and groups", () => {
+        ast = argspecParser.parse("E{\\token^}{{D1}2}");
+        expect(ast).toEqual([
+            {
+                defaultArg: ["D1", "2"],
+                embellishmentTokens: ["\\token", "^"],
+                type: "embellishment",
+            },
+        ]);
+    });
+
     it("Embellishments always return a string", () => {
-        let ast = argspecParser.parse("e{{{x}}y{z}}");
+        ast = argspecParser.parse("e{{x}y{z}}");
         expect(ast).toEqual([
             { type: "embellishment", embellishmentTokens: ["x", "y", "z"] },
         ]);
-        ast = argspecParser.parse("E{{{x}}y{z}}{}");
+        ast = argspecParser.parse("E{{x}y{z}}{}");
+        expect(ast).toEqual([
+            {
+                type: "embellishment",
+                embellishmentTokens: ["x", "y", "z"],
+                defaultArg: [],
+            },
+        ]);
+    });
+    it("Embellishments keep default args", () => {
+        ast = argspecParser.parse("E{{x}y{z}}{{One}{Two}{Three}}");
         expect(ast).toEqual([
             {
                 type: "embellishment",
                 embellishmentTokens: ["x", "y", "z"],
-                defaultArg: { type: "group", content: [] },
+                defaultArg: ["One", "Two", "Three"],
             },
         ]);
     });
diff --git a/packages/unified-latex-util-arguments/libs/gobble-arguments.ts b/packages/unified-latex-util-arguments/libs/gobble-arguments.ts
index a68a2655..94664ec2 100644
--- a/packages/unified-latex-util-arguments/libs/gobble-arguments.ts
+++ b/packages/unified-latex-util-arguments/libs/gobble-arguments.ts
@@ -6,6 +6,7 @@ import {
     parse as parseArgspec,
 } from "@unified-latex/unified-latex-util-argspec";
 import { gobbleSingleArgument } from "./gobble-single-argument";
+import { updateRenderInfo } from "@unified-latex/unified-latex-util-render-info";
 
 /**
  * Gobbles an argument of whose type is specified
@@ -38,7 +39,12 @@ export function gobbleArguments(
             // we need to keep gobbling arguments until we've got them all.
             const remainingTokens = new Set(spec.embellishmentTokens);
             const argForToken = Object.fromEntries(
-                spec.embellishmentTokens.map((t) => [t, emptyArg()])
+                spec.embellishmentTokens.map((t, i) => {
+                    // For empty arguments, we also store their default.
+                    const defaultArg =
+                        "defaultArg" in spec ? spec.defaultArg?.[i] : undefined;
+                    return [t, emptyArg(defaultArg)];
+                })
             );
 
             let { argument, nodesRemoved: removed } = gobbleSingleArgument(
@@ -66,7 +72,10 @@ export function gobbleArguments(
                 spec,
                 startPos
             );
-            args.push(argument || emptyArg());
+            // For empty arguments, we also store their default.
+            const defaultArg =
+                "defaultArg" in spec ? spec.defaultArg : undefined;
+            args.push(argument || emptyArg(defaultArg));
             nodesRemoved += removed;
         }
     }
@@ -87,6 +96,10 @@ function embellishmentSpec(tokens: Set<string>): ArgSpec.Embellishment {
 /**
  * Create an empty argument.
  */
-function emptyArg(): Ast.Argument {
-    return arg([], { openMark: "", closeMark: "" });
+function emptyArg(defaultArg?: string): Ast.Argument {
+    const ret = arg([], { openMark: "", closeMark: "" });
+    if (defaultArg != null) {
+        updateRenderInfo(ret, { defaultArg });
+    }
+    return ret;
 }
diff --git a/packages/unified-latex-util-arguments/tests/get-args-content.test.ts b/packages/unified-latex-util-arguments/tests/get-args-content.test.ts
index 2a6de7d8..d06cda3a 100644
--- a/packages/unified-latex-util-arguments/tests/get-args-content.test.ts
+++ b/packages/unified-latex-util-arguments/tests/get-args-content.test.ts
@@ -1,3 +1,4 @@
+import { describe, it, expect } from "vitest";
 import util from "util";
 import * as Ast from "@unified-latex/unified-latex-types";
 import { attachMacroArgs } from "../libs/attach-arguments";
diff --git a/packages/unified-latex-util-arguments/tests/unifiex-latex-attach-arguments.test.ts b/packages/unified-latex-util-arguments/tests/unifiex-latex-attach-arguments.test.ts
index 64bf5e6c..4bf11989 100644
--- a/packages/unified-latex-util-arguments/tests/unifiex-latex-attach-arguments.test.ts
+++ b/packages/unified-latex-util-arguments/tests/unifiex-latex-attach-arguments.test.ts
@@ -1,3 +1,4 @@
+import { describe, it, expect } from "vitest";
 import { unified } from "unified";
 import { VFile } from "unified-lint-rule/lib";
 import util from "util";
diff --git a/packages/unified-latex-util-pegjs/grammars/xparse-argspec.pegjs b/packages/unified-latex-util-pegjs/grammars/xparse-argspec.pegjs
index a2e6c403..b332d12f 100644
--- a/packages/unified-latex-util-pegjs/grammars/xparse-argspec.pegjs
+++ b/packages/unified-latex-util-pegjs/grammars/xparse-argspec.pegjs
@@ -11,12 +11,16 @@
         const computedOptions = DEFAULT_OPTIONS[type] || {};
         return { type, ...computedOptions, ...options };
     }
+
     /**
-     * Recursively return the content of a group until there are no more groups
+     * Convert a group to a string, preserving {} braces.
      */
-    function groupContent(node) {
+    function groupToStr(node) {
+        if (typeof node !== "object" || !node) {
+            return node;
+        }
         if (node.type === "group") {
-            return node.content.map(groupContent).flat();
+            return `{${node.content.map(groupToStr).join("")}}`;
         }
         return node;
     }
@@ -56,7 +60,7 @@ optional
         }
 
 optional_delimited
-    = "D" braceSpec:brace_spec defaultArg:braced_group {
+    = "D" braceSpec:brace_spec defaultArg:arg {
             return createNode("optional", { ...braceSpec, defaultArg });
         }
     / "d" braceSpec:brace_spec { return createNode("optional", braceSpec); }
@@ -64,20 +68,18 @@ optional_delimited
 optional_star = "s" { return createNode("optionalStar"); }
 
 optional_standard
-    = "O" g:braced_group { return createNode("optional", { defaultArg: g }); }
+    = "O" whitespace g:arg { return createNode("optional", { defaultArg: g }); }
     / "o" { return createNode("optional"); }
 
 optional_embellishment
-    = "e" args:braced_group {
-            // Embellishments ignore groups around tokens. E.g. `e{x}` and `e{{x}}`
-            // are the same.
+    = "e" whitespace args:args {
             return createNode("embellishment", {
-                embellishmentTokens: args.content.map(groupContent).flat(),
+                embellishmentTokens: args,
             });
         }
-    / "E" args:braced_group g:braced_group {
+    / "E" whitespace args:args whitespace g:args {
             return createNode("embellishment", {
-                embellishmentTokens: args.content.map(groupContent).flat(),
+                embellishmentTokens: args,
                 defaultArg: g,
             });
         }
@@ -87,7 +89,7 @@ optional_token
 
 // Required arguments
 required
-    = "R" braceSpec:brace_spec defaultArg:braced_group {
+    = "R" braceSpec:brace_spec defaultArg:arg {
             return createNode("mandatory", { ...braceSpec, defaultArg });
         }
     / "r" braceSpec:brace_spec { return createNode("mandatory", braceSpec); }
@@ -98,6 +100,10 @@ until
             return createNode("until", { stopTokens });
         }
 
+//
+// HELPER RULES
+//
+
 until_stop_token
     = ![{ ] x:. { return [x]; }
     / g:braced_group { return g.content; }
@@ -107,18 +113,42 @@ mandatory = "m" { return createNode("mandatory"); }
 
 // Used to specify a pair of opening and closing braces
 brace_spec
-    = openBrace:$(!whitespace_token .)? closeBrace:$(!whitespace_token .)? {
+    = openBrace:$(!whitespace_token (macro / .))?
+        closeBrace:$(!whitespace_token (macro / .))? {
             return { openBrace, closeBrace };
         }
 
-braced_group
-    = "{" content:($(!"}" !braced_group .) / braced_group)* "}" {
-            return { type: "group", content: content };
+// A `default_arg` is a braced group, but its content will be processed as a string (or array of strings).
+// For example `{foo}` -> `["foo"]` and `{{foo}{bar}}` -> `["foo", "bar"]`
+arg
+    = token
+    / g:braced_group { return g.content.map(groupToStr).join(""); }
+
+args
+    = t:token { return [t]; }
+    / "{" args:(arg / whitespace_token)* "}" {
+            return args.filter((a) => !a.match(/^\s*$/));
         }
 
+braced_group
+    = "{"
+        content:(
+            $(!"}" !braced_group (token / whitespace_token))
+            / braced_group
+        )*
+        "}" { return { type: "group", content: content }; }
+
 whitespace = whitespace_token* { return ""; }
 
 whitespace_token
     = " "
     / "\n"
     / "\r"
+
+macro
+    = $("\\" [a-zA-Z]+)
+    / $("\\" ![a-zA-Z] .)
+
+token
+    = macro
+    / ![{}] !whitespace_token @.
diff --git a/packages/unified-latex-util-pegjs/package.json b/packages/unified-latex-util-pegjs/package.json
index 6cc57c65..5df9d25f 100644
--- a/packages/unified-latex-util-pegjs/package.json
+++ b/packages/unified-latex-util-pegjs/package.json
@@ -67,6 +67,7 @@
                 "index.ts",
                 "libs/**/*.ts",
                 "libs/**/*.json",
+                "grammars/**/*.pegjs",
                 "tsconfig.json",
                 "vite.config.ts"
             ],
@@ -83,6 +84,7 @@
                 "index.ts",
                 "libs/**/*.ts",
                 "libs/**/*.json",
+                "grammars/**/*.pegjs",
                 "tsconfig.json",
                 "vite.config.ts"
             ],
diff --git a/packages/unified-latex-util-render-info/index.ts b/packages/unified-latex-util-render-info/index.ts
index 97737676..93e324f9 100644
--- a/packages/unified-latex-util-render-info/index.ts
+++ b/packages/unified-latex-util-render-info/index.ts
@@ -9,7 +9,7 @@ import { visit } from "@unified-latex/unified-latex-util-visit";
  * *This operation mutates `node`*
  */
 export function updateRenderInfo(
-    node: Ast.Node,
+    node: Ast.Node | Ast.Argument,
     renderInfo: object | null | undefined
 ) {
     if (renderInfo != null) {
diff --git a/tsconfig.test.json b/tsconfig.test.json
index c0b42a32..69bc32e1 100644
--- a/tsconfig.test.json
+++ b/tsconfig.test.json
@@ -1,6 +1,11 @@
 {
     "extends": "./tsconfig.build.json",
-    "include": ["**/*.ts"],
+    "include": [
+        "**/*.ts",
+        // I have no idea why this needs to be included specifically
+        // and none of the other packages do.
+        "packages/unified-latex-types/dist/index.js"
+    ],
     "exclude": [
         "**/*.d.ts",
         "node_modules",
@@ -12,7 +17,7 @@
     "compilerOptions": {
         "rootDir": "./packages",
         "paths": {
-            "@unified-latex/*": ["./packages/*/dist"]
+            "@unified-latex/*": ["./packages/*"]
         },
         "types": ["vitest/globals"]
     }