The full text of VUR5 reads as follows, with some portions bolded for emphasis:
<VUR5> Any Fabricated Parts must be accompanied by documentation that demonstrates the Team’s design and construction process for that Fabricated Part.
a. The minimum acceptable form of documentation is an engineering drawing with multiple views for the part in question. These drawings may be included in a Team’s Engineering Notebook or in a standalone appendix to the Engineering Notebook.
b. Any Fabricated Parts must have been physically fabricated by Team members. For example, parts ordered by the Team and 3D printed by a third party would be prohibited.
c. Teams will be required to provide this documentation to inspectors, Head Referees, or judges at any time. Failure to provide acceptable documentation will result in the part being deemed illegal for use; therefore, <R3>, <R26>, and / or <G1> will apply.
When no VEX-specific definition for a word is provided, the dictionary definition can usually be applied. The dictionary definition for "documentation" is "material that provides official information or evidence or that serves as a record".
We are not going to explicitly specify a minimum form of evidence that must be provided for point "b", as it will be at the inspector's discretion to investigate depending on the part and situation in question. In most cases, the engineering drawing specified by point "a" will be sufficient. If there is further question about the physical fabrication process, examples of possible evidence could include, but are not limited to, pictures or videos of team members fabricating the part.