EDIT Start Of Heading (Ctrl-A) Marks the start of the heading portion of a data stream.
 
EDIT Modern Usage In RS232 Master/Slave configurations, each command from the Master starts with an SOH. This causes the slaves to resynchronize on each command regardless of any prior data errors.

In the XMODEM protocol, each packet is preceded by a three-byte header which begins with the SOH character.

In Graphical User Interfaces, Ctrl-A is generally a shortcut for the select all editing action.
 
EDIT Specification
ISO 1745
ECMA-48 5th Ed. 8.3.127

 
ADD NEWSIMILAR CHARACTERS
 < CHARACTER >  BLOCK PROPERTIES
U+0001 <control>
DEUTSCH : ENGLISH