diff --git a/pages/src/pages/legend/type_categories.md b/pages/src/pages/legend/type_categories.md
deleted file mode 100644
index bbe416ec1..000000000
--- a/pages/src/pages/legend/type_categories.md
+++ /dev/null
@@ -1,84 +0,0 @@
-# Type Categories
-
-## ⚗️ Transformation
-
-Transformation type (⚗️ alembic) transforms the input type from one set to another.
-
-Technically, any type with type parameter are transformation type.
-So that definition is not that helpful in our context.
-
-Instead, we will use transformation type to describe the types that transform the input to a different form within the same category.
-
-## 🧱 Building Types
-
-Building type (🧱 bricks) is a type that can be used to build other types.
-
-(other icons considered: 🧰 toolbox, 🛠️ hammer_and_wrench)
-
-## 💀 Deprecated
-
-Deprecated type (💀 deprecated) is a type that is deprecated and will be removed soon.
-
-## 🛡️ Type Guard
-
-Type guard (🛡️ guard) is a specific type of predicate function in TypeScript that can narrow the type of the input parameter to its subtype.
-The return value of a type guard function is a [type predicate].
-
-## 🚦 Assertion Functions
-
-[Assertion function] (🚦 vertical_traffic_light) is a specific kind of function that narrows the input type using the `asserts condition` syntax.
-
-They act like NodeJS's `assert()` function. The function is used as a statement.
-If the assertion fails, it throws an exception. Otherwise, TypeScript knows the `asserts condition` is met,
-and the input type is narrowed according to the condition in the remaining of the scope.
-
-## 🧪 Testing
-
-Testing types or functions (🧪 test_tube) are designed for testing.
-
-## 🌪️ Filter
-
-Filter (🌪️ tornado) is a type or function that filters the input.
-If the input passes the filter, it is returned unchanged. Otherwise, it returns `never`.
-
-Filter is also known as *pares*, as in [Parse, don't validate].
-
-The returned input can be narrowed if [🔀 distributive] is enabled (on by default).
-
-This means it is better to infer the return type instead of reusing the input type:
-
-```ts
-type IsUndefined<T> = T extends undefined ? T : never
-
-// yes, these are silly, but just an example
-type Bad<T> = IsUndefined<T> extends T ? T : never
-type Good<T> = IsUndefined<T> extends infer R ? R : never
-
-type R1 = Bad<undefined | number> // undefined | number
-type R2 = Good<undefined | number> // undefined
-```
-
-(other icons considered: ↪️👉🚋⏩🐾🔑🚪💂🧲🙅‍♂️🪚)
-
-## 🎭 Predicate
-
-Predicate (🎭 performing_arts) is also known as *validate* or *logical*.
-If the input satisfies the predicate, it returns `true`. Otherwise, `false`.
-
-(other icons considered: ⭕)
-
-## 🏃 Runtime
-
-Runtime (🏃 runner) means the utility (e.g. a function) has runtime effect.
-
-## Others
-
-- 👽 *alias* (:alien:): Alias of another type
-- 💥 *immediate* (:boom:): The effect of the type can be observed immediately during development
-- 🩳 *shortcut* (:shorts:): Shortcut or convenient types
-- 🦴 *utilities* (:bone:): provide various functionalities (other icons considered: 🔧🔨)
-
-[type predicate]: https://www.typescriptlang.org/docs/handbook/2/narrowing.html#using-type-predicates
-[Assertion function]: https://www.typescriptlang.org/docs/handbook/release-notes/typescript-3-7.html#assertion-functions
-[Parse, don't validate]: https://lexi-lambda.github.io/blog/2019/11/05/parse-don-t-validate/
-[🔀 distributive]: ./type_options.md#🔀-distributive
diff --git a/pages/src/pages/legend/type_options.md b/pages/src/pages/legend/type_options.md
deleted file mode 100644
index 8b4687801..000000000
--- a/pages/src/pages/legend/type_options.md
+++ /dev/null
@@ -1,20 +0,0 @@
-# Type Options
-
-These are typical options available ti the types and what do they mean.
-
-## 🔀 Distributive
-
-Distributive (🔀 twisted_rightwards_arrows) means each value in a union type will be evaluated separately in conditional types,
-so both branches may be executed.
-
-```ts
-type R = IsUndefined<string | undefined> // true | false -> boolean
-```
-
-## 📌 Exact
-
-Exact (📌 pushpin) means type comparison will be performed strictly, treating subtype as separate types.
-
-```ts
-type R1 = IsString<'a', { exact: true }> // false
-```