TOGAF uses a version numbering convention to illustrate the evolution of the Baseline and Target Architecture Definitions. Which version number in this convention indicates a high-level outline of the

Version 1.0 indicates a first full architecture definition, which is more detailed and stable than a high-level outline.

Version 0.9 suggests a nearly complete architecture definition, close to its first full release, and is more detailed than an outline.

Version 0.5 implies a moderately well-defined draft architecture, more developed than a high-level outline but not yet complete.

Version 1.5 indicates a minor update or revision to a previously stable Version 1.0 architecture.

Version 0.1 in the TOGAF architecture version numbering convention signifies a high-level outline or initial draft of the architecture, typically produced early in Phase A: Architecture Vision. This version represents a preliminary sketch or conceptual view, often used to gain initial stakeholder consensus before significant detailed work begins.