diff --git a/Skills/JavaScript.md b/Skills/JavaScript.md
index 0ff8fc89..8d5af8bc 100644
--- a/Skills/JavaScript.md
+++ b/Skills/JavaScript.md
@@ -1,122 +1,122 @@
 ## JavaScript
 
 - Language
-  - `Object`
-  - `Function`
-  - `Boolean`
-  - `Number`
-  - `BigInt`
-  - `String`
-  - `Symbol`
-  - `Infinity`
-  - `NaN`
-  - `undefined`
-  - `null`
-  - `this`
-  - `instanceof`
-  - `...spread`
-  - `...rest`
-  - `typeof`
-  - Destructuring
-  - Generators
-  - Iterators
-  - Async generator
-  - Async iterator
-  - Chaining
-  - Optional chaining
-  - IIFE
-  - Async IIFE
+  - `Object`u
+  - `Function`u
+  - `Boolean`u
+  - `Number`u
+  - `BigInt`u
+  - `String`u
+  - `Symbol`u
+  - `Infinity`u
+  - `NaN`u
+  - `undefined`u
+  - `null`u
+  - `this`u
+  - `instanceof`u
+  - `...spread`u
+  - `...rest`u
+  - `typeof`u
+  - Destructuring u
+  - Generators u
+  - Iterators u
+  - Async generator h
+  - Async iterator h
+  - Chaining u
+  - Optional chaining h
+  - IIFE 
+  - Async IIFE 
   - `global`
   - `globalThis`
-  - `window`
-  - Getters and setters
-  - `__proto__`
-  - `prototype`
-  - Equality operators
-  - Logical operators
-  - Logical Assignment
-  - Bitwise operators
-  - Ternary operator
-  - `void`
-  - `yield`
-  - `await`
-  - Template literal
-  - Strict mode
-  - Hoisting
-  - `delete`
-  - `in`
-  - `super`
-  - `eval`
-  - `static`
-  - `Number.parseInt`
-  - `Number.parseFloat`
-  - Property descriptors
-  - Sealing properties
-  - Freezing properties
-  - Computed properties
-  - Instance class fields
-  - Static class fields
-  - Private class fields
-  - Private class methods
+  - `window` u
+  - Getters and setters u
+  - `__proto__` k
+  - `prototype` k
+  - Equality operators u
+  - Logical operators u
+  - Logical Assignment u
+  - Bitwise operators u
+  - Ternary operator u
+  - `void` h
+  - `yield` 
+  - `await` u
+  - Template literal u
+  - Strict mode u
+  - Hoisting u
+  - `delete` u
+  - `in` u
+  - `super` u
+  - `eval` u
+  - `static` u
+  - `Number.parseInt` u
+  - `Number.parseFloat` u
+  - Property descriptors 
+  - Sealing properties 
+  - Freezing properties 
+  - Computed properties h
+  - Instance class fields u
+  - Static class fields u
+  - Private class fields u
+  - Private class methods u
 - Statements
-  - `if`
-  - `while`
-  - `do..while`
-  - `for`
-  - `for..in`
-  - `for..of`
-  - `for await`
-  - `throw`
-  - `break`
-  - `continue`
-  - `import`
-  - `export`
-  - `label`
-  - `try..catch`
-  - `switch`
-  - `class`
-  - `extends`
-  - `with`
-  - `new`
+  - `if` u
+  - `while` u
+  - `do..while` u
+  - `for` u
+  - `for..in` u
+  - `for..of` u
+  - `for await` u
+  - `throw` u
+  - `break` u
+  - `continue` u
+  - `import` u
+  - `export` u
+  - `label` h
+  - `try..catch` u
+  - `switch` u
+  - `class` u
+  - `extends` u
+  - `with` h
+  - `new` u
 - Functions
-  - Arrow function
-  - Async function
-  - Function declaration
-  - Function expression
-  - Default parameters
-  - Functional object
-  - `Function.prototype.call`
-  - `Function.prototype.bind`
-  - `Function.prototype.apply`
-  - `return`
+  - Arrow function u
+  - Async function u
+  - Function declaration u
+  - Function expression u
+  - Default parameters u
+  - Functional object u
+  - `Function.prototype.call` k
+  - `Function.prototype.bind` k
+  - `Function.prototype.apply` k
+  - `return` u
 - Data structures
-  - `Array`
-  - `Map`
-  - `Set`
-  - `WeakMap`
-  - `WeakSet`
+  - `Array` u
+  - `Map` u
+  - `Set` u
+  - `WeakMap` h
+  - `WeakSet` h
   - Typed arrays
-  - Mixins
-  - `Object.assign`
+  - Mixins h
+  - `Object.assign` k
 - Standard classes and namespaces
-  - `Proxy`
-  - `RegExp`
-  - `Date`
-  - `Math`
-  - `Reflect`
-  - `Error`
-  - `Atomics`
-  - `JSON`
-  - `WeakRef`
-  - `FinalizationRegistry`
-  - `Intl`
-  - `Promise`
-  - `console`
-  - Timers
+  - `Proxy` h
+  - `RegExp` u
+  - `Date` u
+  - `Math` u
+  - `Reflect` 
+  - `Error` u
+  - `Atomics` h
+  - `JSON` u
+  - `WeakRef` 
+  - `FinalizationRegistry` h
+  - `Intl` h
+  - `Promise` u
+  - `console` u
+  - Timers u
 - Infrastructure
-  - V8
-  - Node.js
-  - npm
-  - prettier
-  - MDN
-  - TC39
+  - V8 k
+  - Node.js u
+  - npm u
+  - prettier k
+  - MDN u
+  - TC39 
diff --git a/Skills/NodeJS.md b/Skills/NodeJS.md
index bd891457..c7657ff0 100644
--- a/Skills/NodeJS.md
+++ b/Skills/NodeJS.md
@@ -11,14 +11,14 @@
   - I/O-bound, CPU-bound, memory-bound tasks
   - Interactive applications (close to real-time)
 - Modularity, layers and dependencies
-  - CommonJS modules
-  - ECMAScript modules
+  - CommonJS modules u
+  - ECMAScript modules u
   - Module `node:module`
   - Caching in CJS and ESM
   - Modules as singletons
   - Contexts and scripts module `node:vm`
-  - Dependencies: `npm`, `node_modules`
-  - Files `package.json`, `package-lock.json`
+  - Dependencies: `npm`, `node_modules` u
+  - Files `package.json`, `package-lock.json` u
   - Module-based permissions model
   - Isolation with modularity
   - Dependency injection
@@ -77,7 +77,7 @@
   - Long polling
   - REST
   - RPC
-  - Routing
+  - Routing 
   - DoS
   - DDoS
   - XSS
diff --git a/Skills/Programming.md b/Skills/Programming.md
index e976b503..706e9403 100644
--- a/Skills/Programming.md
+++ b/Skills/Programming.md
@@ -1,73 +1,73 @@
 ## Programming fundamental concepts
 
 - Concepts
-  - Model
-  - Modeling
-  - Subject domain
-  - Algorithm
-  - Syntax
-  - Semantics
-  - Abstraction
-  - Paradigm
-  - Programm
-  - Programming paradigm
-  - Programming language
+  - Model u
+  - Modeling u
+  - Subject domain u
+  - Algorithm u
+  - Syntax u
+  - Semantics u
+  - Abstraction u
+  - Paradigm u
+  - Programm u
+  - Programming paradigm u
+  - Programming language u
   - Contract
-  - Module
-  - Library
-  - Package
-  - Component
-  - Framework
-  - Platform
-  - Source code
-  - Object code
-  - Machine code
+  - Module u
+  - Library u
+  - Package u
+  - Component u
+  - Framework u
+  - Platform u
+  - Source code u
+  - Object code u
+  - Machine code u
   - Microcode
-  - Software engineering
-  - Decomposition
+  - Software engineering u
+  - Decomposition u
   - Control flow
   - Data flow
-  - Code reuse
+  - Code reuse u
   - Defensive programming
-  - Don't repeat yourself (DRY)
+  - Don't repeat yourself (DRY) u
   - KISS principle
 - Syntax and concepts
-  - Value
-  - Identifier
-  - Variable
-  - Constant
-  - Scalar
-  - Literal
-  - Expression
-  - Heap
-  - Function
-  - Procedure
-  - Method
-  - Class
-  - Prototype
-  - Event
-  - Type
-  - Flag
-  - Lexical scope
-  - Code block
-  - Conditions
-  - Loops
-  - Assignment
-  - Regular expression
-  - Interface
-  - Namespaces
-  - Call stack
-  - Naming conventions
-  - Coding conventions
-  - Camel case
-  - Snake case
+  - Value u
+  - Identifier u
+  - Variable u
+  - Constant u
+  - Scalar u
+  - Literal u
+  - Expression u
+  - Heap u
+  - Function u
+  - Procedure u
+  - Method u
+  - Class u
+  - Prototype u
+  - Event u
+  - Type u
+  - Flag u
+  - Lexical scope u
+  - Code block u
+  - Conditions u
+  - Loops u
+  - Assignment u
+  - Regular expression u
+  - Interface u
+  - Namespaces u
+  - Call stack u
+  - Naming conventions u
+  - Coding conventions u
+  - Camel case u
+  - Snake case u
   - Kebab case
-  - Trailing commas
+  - Trailing commas u
   - Return early
   - Fail-fast
 - Types
-  - Primitive types
-  - Reference types
+  - Primitive types u
+  - Reference types u
   - Type systems
   - Strong typing
   - Weak typing
@@ -81,92 +81,92 @@
   - Covariance
   - Contravariance
 - Functions
-  - Signature
-  - Argument
-  - Parameter
-  - Pure function
-  - Lambda expression
-  - Side effects
+  - Signature u
+  - Argument u
+  - Parameter u
+  - Pure function u
+  - Lambda expression u
+  - Side effects u
   - Closure
   - Partial application
   - Currying
   - Higher order
-  - Recursion
+  - Recursion u
   - Tail call optimisation
-  - Callback
-  - Listener
-  - Composition
+  - Callback u
+  - Listener u
+  - Composition u
   - Pipe
-  - Memoize
-  - Wrapper
+  - Memoize u
+  - Wrapper u
   - Functor
   - Monad
   - Monoid
   - Generator
   - Coroutine
 - Data structures
-  - Array
-  - Structure
-  - Record
-  - Enum
-  - Instance
-  - Object
-  - Collection
-  - Set
-  - Hash table
-  - Linked list
-  - Doubly list
-  - Unrolled list
-  - Circular list
-  - Queue
-  - Stack
-  - Deque
-  - Tree
-  - Graph
-  - Iterator
-  - Mutable state
-  - Immutable state
-  - Serialization
-  - String parsing
-  - JSON
-  - JSON5
-  - YAML
+  - Array u
+  - Structure u
+  - Record k
+  - Enum k
+  - Instance u
+  - Object u
+  - Collection u
+  - Set u
+  - Hash table u
+  - Linked list h
+  - Doubly list h
+  - Unrolled list h
+  - Circular list h
+  - Queue u
+  - Stack u
+  - Deque h
+  - Tree h
+  - Graph h
+  - Iterator u
+  - Mutable state k
+  - Immutable state k
+  - Serialization h
+  - String parsing h
+  - JSON u
+  - JSON5 h
+  - YAML h
 - Networking
   - DNS
   - CDN
   - CORS
-  - IPv4
+  - IPv4 k
   - IPv6
   - NAT
-  - URL
+  - URL u
   - URN
-  - URI
+  - URI u
 - Process and tools
-  - Compiler
-  - Just-in-time compilation
-  - Ahead-of-time compilation
-  - Transpiler
-  - Linter
+  - Compiler u
+  - Just-in-time compilation u 
+  - Ahead-of-time compilation u
+  - Transpiler k
+  - Linter k
   - Polyfill
-  - Interpreter
+  - Interpreter u
   - Linker
   - Dynamic linking
   - Static linking
-  - Runtime
+  - Runtime u
   - Virtual machine
   - Register-based VM
   - Stack-based VM
   - Containerization
-  - Debugger
+  - Debugger u
   - Tracing
   - Garbage collection
-  - Refactoring
-  - Code review
-  - Exception
-  - Unittesting
-  - git
-  - Github
-  - Docker
+  - Refactoring u
+  - Code review u
+  - Exception u
+  - Unittesting k
+  - git u
+  - Github u
+  - Docker h
   - Kubernetes
   - GCC
   - LLVM
@@ -203,7 +203,7 @@
   - Yo-yo problem
 - Runtimes and virtual machines
   - Bytecode
-  - V8
+  - V8 h
   - VJM
   - CLR
   - Mono
@@ -214,11 +214,11 @@
   - Ring
   - Virtual memory
   - File system
-  - Linux
-  - Unix
+  - Linux k
+  - Unix k
   - BSD
-  - MacOS
-  - Windows
+  - MacOS k
+  - Windows u
   - Real-time OS
   - Embedded OS
 - Standards
@@ -229,7 +229,7 @@
   - IANA
   - IEEE
   - Base64
-  - ECMA
+  - ECMA u
   - ICANN
   - ISO
   - MIME