1. Template substitution use cases

2. Substitution of a complete tier spec section 13 web_app [WebApplication] web_server [WebServer] server [Compute] db [Database] database [Database] dbms [DBMS] server [Compute] Cap Req Cap Req Declares to be substitution for type Database, thus exposes all reqs/caps etc. as defined by type Database. host requirement is bound internally, so binding in substitution context would violate.

3. Substitution of only software part of a tier web_app [WebApplication] web_server [WebServer] server [Compute] db [???] database [Database] dbms [DBMS] Cap Req Cap Req There is currently no type that exposes the aggregated reqs, caps and properties/attributes of Database and DBMS. If we had such a type, current substitution would handle that use case. Req