Sinclair QL Beginner's Manual page 30

To finish the automatic production of line numbers use the BREAK sequence:
Hold down the CTRL and press the SPACE bar. This will produce the message:
130 not complete
and line 130 will not be included in your program.
If you make a mistake which does not cause a break from automatic numbering, you can continue
and EDIT the line later. If you want to start at some particular line number say 600, and use an
increment other than 10 you can type, for an increment of 5:
AUTO 600,5
Lines will then be numbered 600, 605, 610, etc.
To cancel AUTO, press CTRL and the SPACE bar at the same time.
EDITING A LINE
To edit a line simply type EDIT followed by the line number for example:
EDIT 110
The line will then be displayed with the cursor at the end thus:
110 PRINT "Second"
You can move the cursor using:
 one place left
 one place right
To delete a character to the left use:
CTRL with 
To delete the character in the cursor position type:
CTRL with 
and the character to the right of the cursor will move up to close the gap.
USING MICRODRIVE CARTRIDGES
Before using a new Microdrive cartridge it must be formatted. Follow the instructions in the
Introduction. The choice of name for the cartridge follows the same rules as SuperBASIC identifiers,
etc. but limited to only 10 characters. It is a good idea to write the name of the cartridge on the
cartridge itself using one of the supplied sticky labels. You should always keep at least one back-up
copy of any program or data. Follow the instructions in the Information section of the User Guide.
If you FORMAT a cartridge which holds programs and/or data,
SAVING PROGRAMS
WARNING
ALL the programs and/or data will be lost