To build a TEI pizza, take...

• the core tagsets
• the base of your choice
• the toppings of your choice
• (optionally) a reference to your extensions

 <!DOCTYPE TEI.2 SYSTEM "tei2.dtd" [
  <!ENTITY % tei.prose    "INCLUDE" >
  <!ENTITY % tei.analysis "INCLUDE" >
  <!ENTITY % tei.extensions.ent 
                SYSTEM "myMods.ent" >
  <!ENTITY % tei.extensions.dtd 
                SYSTEM "myMods.dtd" >
]>
<tei.2>.....</tei.2>