Creating a Transposing Instrument

I saw there was a thread about guitar notation which mentioned different open tunings.
I write and play a fretless guitar which is tuned to D standard ie down a tone.
I usually write Bb charts for this. Is their an easy way to create a Bb chart for a guitar? I can’t find any way of customising or creating a new instrument. How is the guitar notation update going? Can anyone suggest a work around for my need?
Cheers, Tom

Dear Tom,
Dorico 3 will be (partly) about guitar notation, probably in a very comprehensive way. Until this game-changer update comes, anything we can suggest you on that matter will be workarounds.
Anyway, you can select a Bb trumpet instrument, rename it (in Setup mode, open the player’s card, right-click the name of the instrument and choose Edit name in the contextual menu) and you’re set with an instrument in Bb. You can add a staff below if needed (right click the staff and in the context menu > Staff > Add staff below).
Hope this helps

Thanks Marc,
I thought that might be the answer! That is pretty much what I have been doing in Sibelius. Just hoping!? :smiley:
Cheers, Tom

Would one have to add an octave-transposition Expression Map as well, or does the HALion guitar sound automatically transpose?