It moves around based on process. Pin in Paste is the topside/component side. Selective solder is the side opposite the component. Rare hand soldering for components only accessible from the top side, not the preferred situation for DFM. Select components in module assemblies come to mind. Some designers do not accept sockets. Inspection callout should include the situation so that the Inspector does not reject valid joints. Had large problem when selective solder connector went to pin in paste with Inspectors rejecting good joints. Larry Dzaugis