The other-technical element is used to define any technical indications not yet in the MusicXML format. The smufl attribute can be used to specify a particular glyph, allowing application interoperability without requiring every SMuFL technical indication to have a MusicXML element equivalent. Using the other-technical element without the smufl attribute allows for extended representation, though without application interoperability.
The
<other-technical>element.The other-technical element is used to define any technical indications not yet in the MusicXML format. The smufl attribute can be used to specify a particular glyph, allowing application interoperability without requiring every SMuFL technical indication to have a MusicXML element equivalent. Using the other-technical element without the smufl attribute allows for extended representation, though without application interoperability.
See
https://www.w3.org/2021/06/musicxml40/musicxml-reference/elements/other-technical/