How do I create custom fold regions with markers in my code?

Explanation

Setting foldmethod=marker lets you define fold boundaries using special comment markers — {{{ to start a fold and }}} to end it. This gives you explicit control over exactly what gets folded.

How it works

:set foldmethod=marker

Vim looks for {{{ and }}} in your file (typically inside comments) and creates folds between them.

Example

" Configuration {{{1
set number
set relativenumber
set cursorline

" Key Mappings {{{1
nnoremap <leader>w :w<CR>
nnoremap <leader>q :q<CR>

" Auto Commands {{{1
autocmd BufWritePre * :%s/\s\+$//e
" }}}

The numbers after {{{ indicate fold levels — {{{1 creates a level-1 fold, {{{2 creates a nested level-2 fold.

Creating folds on the fly

" Select text and create a fold marker
zf      " In visual mode, wraps selection with markers

" Or manually insert markers
" Start: {{{  
" End: }}}

Custom markers

You can change the fold markers:

:set foldmarker=<<<,>>>    " Use <<< and >>> instead

Tips

• Marker folding is ideal for vimrc files, configuration files, and long documentation
• Add fold level numbers for nested sections: {{{1, {{{2, {{{3
• Use zf in visual mode to quickly wrap a selection with markers
• The foldmethod=marker setting can be set per-file via modelines:

  " vim:foldmethod=marker