Diagonal Fraction. You can change the tilt by selecting the whole thing and clicking on Change (the Yin-Yang) icon.
Fraction.
Diacritical Mark, which encloses what it marks. You can change which mark it has by selecting the whole thing and clicking on Change (the Yin-Yang) icon.
Vertical Fences. You can change the fence symbols to be on the sides by selecting the whole thing and clicking on Change (the Yin-Yang) icon.
{ Fence } composite. You can change the fence symbol on the left and the right by selecting the whole thing and clicking on Change (the Yin-Yang) icon.
A space between Matrix elements. To select the whole matrix, double click here. Matrices normally come without enclosing parentheses so that you can add whatever style you want.
A String with a Ruler. To move tab stops, drag them along the ruler. To change the width, move the square on the right edge of the ruler.
A String with a Ruler. To see the ruler, click on the Ruler icon on the Palette.
A String of characters and composites. To edit, click, drag and type normally.
A Tab character. Separates columns in a string with a ruler.
A Thin Space character. To insert another one, click on the blank icon on the Palette.
A space character. To see all space characters, click on the Ruler or Guide icons in the palette.
A special symbol. To insert another one, click on an appropriate button on the palette.
A character in your expression. To replace, drag over it and start typing.