Substitution is the one-time, permanent copying of any content on Tractor Wiki. It differs from transclusion, which continually updates as the linked-to content changes. To substitute, add subst: after the opening braces, as in {{subst:page name}}. For example: substitution {{subst:Medicine}} in contrast to transclusion {{Medicine}}. This page also lists templates that should either always or never be substituted except in the Wikipedia namespace. Automated tools (bots) that do such replacements will never be used on the original template pages.