VIM mapping command

fun! Ysml()
    nmap <buffer> <silent> di :call DK1()<CR>
    nnoremap <buffer> <silent> <cr> :call DK2()<CR>
" Only on ml file , Only for buffer ."
endf

here , I've been thinking cr Affected Command line window Of mapping , What to do with . Later I saw <buffer> 了 , add , Just fine , No longer Affect command line mapping .