Use Tags and Smart Folders in Notes on your iPhone and iPad - Apple Support

Use tags to quickly categorize your notes so you can easily find them later. Just add one or more tags — like #work or #shopping — anywhere in any note. You can also use tags together with existing folders to search and filter your notes across multiple folders.

Notes on iPhone is an Incredibly Powerful App (If You Know About These Features)

Use Notes on your iPhone, iPad, and iPod touch - Apple Support

Use Notes on your iPhone, iPad, and iPod touch - Apple Support (CA)

Organize your messy Notes app with these simple tips

How to use Smart Folders in Notes app on iPhone, iPad, Mac

How To Quickly Organize iPhone Notes Using Tags & Smart Folders

How to Use Smart Folders in Notes App on iPhone, iPad and Mac - Guiding Tech

Select, cut, copy, and paste text on iPhone - Apple Support

A Closer Look at Apple Notes's Smart Folders – The Sweet Setup