How do I create a soft return (shift+Enter)?

FrameMaker 11

DITA 1.2

Is it possible using FM 11 and DITA 1.2 to use a soft return (as in Shift+Enter)? There are times when I want to avoid bad line breaks in a line of code or when I just want to keep a line with the previous line rather than having the extra space generated by a hard return.

Using a soft return disappears as soon as I save my file and reopen it. By "disappears" I mean it acts simply like a space rather than any type of return.

Thanks in advance,

Marsha