(SSI) The facility provided by moSt {web ServerS}, e.g. {NCSA httpd}, to replace Special {tag}S in an HTML file with the contentS of another file before the file iSSent out by the Server, i.e. an HTMLmacro. {NCSA httpd tutorial (http://hoohoo.ncSa.uiuc.edu/docS/tutorialS/includeS.html)}. (1996-09-08)