Where exactly in the meta.xml file do I specify the name usd for the folder that contains my theme?

The sample theme uses the text LEGACY for the folder name but the meta.xml file does not listthe text LEGACY anywhere in it.   So where exactly in the meta.xml file does one specify the ext LEGACY (in the case of the sample LEGACY theme) or whatever name ou’ve specifed for the folder that conatins your theme?

BTW - I thought it would the set of Title tags but if thats true then the provided sample LEGACY theme will notwork because it has listed in the Title tags the  text MOCHI (Default).

Any ideas on this?

If you change the info in the meta.xml, it will apply it to the theme you make.