I don't understand the mod_rewrite Flag [L]

问题

What is the answer of the behavior from the following RewriteCond/RewriteRule?

RewriteCond %{HTTP_REFERER} ""
RewriteRule ^(.*)$ $1?x=%{HTTP_REFERER} [QSA,NC]
RewriteRule ^(.*)$ $1?y=%{HTTP_REFERER} [QSA,NC]
RewriteRule ^(.*)$ $1?z=%{HTTP_REFERER} [QSA,NC,L]

result: z=&y=&x=

RewriteCond %{HTTP_REFERER} ""
RewriteRule ^(.*)$ $1?x=%{HTTP_REFERER} [QSA,NC]

RewriteCond %{HTTP_REFERER} ""
RewriteRule ^(.*)$ $1?y=%{HTTP_REFERER} [QSA,NC]

RewriteCond %{HTTP_REFERER} ""
RewriteRule ^(.*)$ $1?z=%{HTTP_REFERER} [QSA,NC,L]

result: z=&y=&x=

RewriteCond %{HTTP_REFERER} ""
RewriteRule ^(.*)$ $1?x=%{HTTP_REFERER} [QSA,NC,L]

RewriteCond %{HTTP_REFERER} ""
RewriteRule ^(.*)$ $1?y=%{HTTP_REFERER} [QSA,NC,L]

RewriteCond %{HTTP_REFERER} ""
RewriteRule ^(.*)$ $1?z=%{HTTP_REFERER} [QSA,NC,L]

result: x=

I don't understand it.

I know the doc page. https://httpd.apache.org/docs/2.4/rewrite/flags.html

来源：https://stackoverflow.com/questions/61395182/i-dont-understand-the-mod-rewrite-flag-l