/MODIFY
  /NOMODIFY

  Specifies whether the buffer created for the input file  is  modifiable
  or  unmodifiable.   If  you  specify  the /MODIFY qualifier, the LSEDIT
  command creates a modifiable buffer.   If  you  specify  the  /NOMODIFY
  qualifier,  the  LSEDIT command creates an unmodifiable buffer.  If you
  do not specify either qualifier, LSE determines the buffer's modifiable
  status  from  the  read-only/write  setting.   By  default, a read-only
  buffer is unmodifiable and a write buffer is modifiable.