From a mail:
Currently there is the Split file command that will split a file based on size.
I would like to suggest that a option to split at a specific position (like the current cursor position).
Example, when spiting a mailbox, the split needs to happen between messages at the split point.
Currently I need to split the file by size then move the partial message from the tail of the first file to the head of the next file.
While that would be the most useful for most people, for what I was doing tonight, this would have been handy,
Split by size, and keyword. The user selects a Size to split at, and enters a keyword. HxD then goes to the position where it would split by Size then does a "Search for" the keyword with "Search Direction" "backward". So that the break happens at the keyword closest to but smaller in size than Size.