Metadata should contain a license field

[nilshoffmann]

In order to express that an mzTab-M file is licensed for derivative works, a new license field should be added to the metadata section. Typically, only one license SHOULD be reported. Multiple licenses may be reported to distinguish between academic and commercial use.

MTD    license[1]    [SWO, SWO:1000049, "CC0 1.0", ]

In this case, adding an additional cv element in the metadata section is necessary to register the SWO (software ontology: Software Ontology) within the mzTab-M file.