Spanish to English Tech/Engineering Engineering (general) Construction of train depot

This is a description of what the building design project (proyecto) should include. It is part of a list of sections to be included in the Specifications documentation:
III. Pliego de condiciones

Pliego de cláusulas administrativas
Disposiciones generales
Disposiciones facultativas
Disposiciones económicas
Pliego de condiciones técnicas particulares

I reckon Disposiciones is Provisions. My trouble is that facultativo/a in construction is usually related to technical supervision or specifications (see dirección facultativa, for example, which is usually given as site management, works supervision, etc)

However, facultativa also means optional, sometimes

All input gratefully received