Edit

Sel - works for 3d editing and text editor (duplicate works only for 3d modelling)

Rotate - Change projection -> Imagine you have a 3d model and you want to print it, but you need to rotate it by say 90 degrees in order to make the object printable, no one wants to think about, which axis you need to rotate the object around, instead you just choose to change what you see into

Hollow - hollows only first object in selection sides have thickeness of the grid size

CSG Subtract - cut models with selection

Project preferences - don't touch it! But "Meter stands for unit" - if you want say to create a 1 kilometer surface you decrease this number from 6400 default, this also affects grid size, this is why there is no metric in grid size.


Entity:

Group/Ungroup - group selected, ungroup selected

Properties - choose color, transparency and pattern type


Move -> See offsetting


Set size -> Set the size of selection

Scale -> Scale selection

Snap: