Proxies
Proxies were the historical way in Blender to allow some local editing of linked data-blocks. This was mostly aimed at character animation.
They are now fully deprecated as of Blender 3.0, replaced by the new Library Overrides.
Los reemplazos existentes en antiguos ficheros-blend serán convertidos a redefinición de bibliotecas cuando se abran en Blender 3.2.