The Bootstrap Kernel (BSK) subset omits the following features:

• BLUEPRINT compilation unit
• GENLIB directive to invoke external template engine
• Multi-dimensional array types
• Immutable types and supporting features
• Coroutine types and supporting features
• Opaque fields in record type definition
• Syntax binding for numeric data types
• All language defined pragmas, except INLINE, DEPRECATED, PRIVATETO, FFI and FFIDENT

The following features are optional only

• built-in module ATOMIC
• built-in module ASSEMBLER