Commands use the Label information from officecfg/registry/schema/org/openoffice/Office/UI/Commands.xcs - or alternatives in special UI, for example when shown in a context. The Notebookbar is such special UI and requires often shorter strings. For example, bug 160287 reports trouble with Print Directly, which is amended by the printer name. These issues would be solved if we had a special NotebookbarLabel (with fallback to Label, of course).
+1 Would move MUFFIN along and improve the NB framework, don't forget the label support needed for extension authors.
+1 as well Not only do we need special strings for the Tabbed UI, but we also need the ability to wrap them. For instance, consider the "Merge and Center Cells" command in Calc. It takes a wide space in the Tabbed UI because it must be written in a single line. In Excel, the Ribbon UI has many entries whose label use 2 lines of text (f.i. Conditional Formatting). And when they're too long, the strings elide, which is also an option for us. This makes a much better layout, with a more predictable total width.