How do you turn the new screen elements on and off using the keyboard? How about the not-so-new ones? See this table:
| Element | On | Off | Toggle |
| Advanced Render Settings | RPPREF | RPPREFCLOSE | |
| Clean Screen | CLEANSCREENON | CLEANSCREENOFF | Ctrl+0 |
| Command line | COMMANDLINE | COMMANDLINEHIDE | Ctrl+9 |
| dbConnect | DBCONNECT | DBCCLOSE | Ctrl+6 |
| DesignCenter | ADCENTER | ADCCLOSE | Ctrl+2 |
| Layer palette | LAYER | LAYERCLOSE | |
| Lights | LIGHTLIST | LIGHTLISTCLOSE | |
| Markup Set Manager | MARKUP | MARKUPCLOSE | Ctrl+7 |
| Materials | MATERIALS | MATERIALSCLOSE | |
| Menu bar | MENUBAR 1 | MENUBAR 0 | |
| NavCube | NAVCUBEDISPLAY 1 | NAVCUBEDISPLAY 0 | |
| Properties palette | PROPERTIES | PROPERTIESCLOSE | Ctrl+1 |
| Quick calc | QUICKCALC | QCCLOSE | Ctrl+8 |
| Ribbon | RIBBON | RIBBONCLOSE | |
| Rollover tool tips | ROLLOVERTIPS 1 | ROLLOVERTIPS 0 | |
| Sheet Set Manager | SHEETSET | SHEETSETHIDE | Ctrl+4 |
| Status bar | STATUSBAR 1 | STATUSBAR 0 | |
| Status bar tray icons |
TRAYICONS 1 | TRAYICONS 0 | |
| Tool palette | TOOLPALETTES | TOOLPALETTESCLOSE | Ctrl+3 |
| Tool tips | TOOLTIPS 1 | TOOLTIPS 0 | |
| Visual Styles | VISUALSTYLES | VISUALSTYLESCLOSE |
For Status bar icons you list TRAYICONS 1/0, but in my copy of AutocAD 2009 this sysvar toggles the display of tray icons only (these are the warning icons, such as TrustedDWG).
There is a separate system variable for toggles the status and drawing bars: statusbar 0/1/2/3.
You are, Sir, entirely correct. Thank you for pointing that out. I have updated the table. I have ignored the drawing status bar for simplicity (and because I think it’s pointless).