Reference for Tahorot 6:10

הָאִסְטְוָנִית, רְשׁוּת הַיָּחִיד לַשַּׁבָּת וּרְשׁוּת הָרַבִּים לַטֻּמְאָה. חָצֵר שֶׁהָרַבִּים נִכְנָסִים בָּזוֹ וְיוֹצְאִים בָּזוֹ, רְשׁוּת הַיָּחִיד לַשַּׁבָּת וּרְשׁוּת הָרַבִּים לַטֻּמְאָה:

A colonnade is a private domain regarding Shabbat but a public domain regarding impurity. A courtyard which the masses enter into through one [entrance] and exit through the other is a private domain regarding Shabbat but a public domain regarding impurity.

Jastrow