You can insert symbols by using the Edit > 
Insert
from Character Map... action. This displays the Character Map dialog box.
The Character Map Dialog Box
The Character Map dialog box allows you to visualize all characters available in a font, pick the character you need and insert it in the document you are editing. You can also access this dialog if you use the action.
Use the Font box to choose the font for which you want to display characters. To see only a certain range of characters, use the Unicode Block box. This will filter the number of characters displayed, showing only a contiguous range of characters corresponding to the selected block. Unassigned characters are displayed as empty squares.
- Compact - matrix-like representation which displays only characters.
- Details - displays the available characters in a tabular format, presenting their decimal and hexadecimal value along with their description.
Use the Search field to search for a character by one of the following attributes:decimal value, hexadecimal value or description. Selecting the description option places the focus on the Details tab. In case you enter a character description in the Search field, the description option is selected automatically. The searching operation starts as soon as you start typing characters in the Search field.
Press the Insert button to insert the selected character in the current editor at caret position. You will see the character in the editor if the editor font is able to render it. The Copy button copies it to the clipboard without inserting it in the editor. You can see the name and range name of a character either at the bottom of the dialog, or when hovering the mouse cursor over the character.
The Character Map dialog cannot be used to insert Unicode characters in the grid version of a document editor. Accordingly, the Insert button of the dialog will be disabled if the current document is edited in Grid mode.