でなくては is used in negative sentences. (thing that must be)でなくては(what can't or won't be done without first part).
sarruby
でなくては書けない=だけが書ける=以外には書けない=をおいて他には書けない can be used for #5459, and with appropriate modification for #5017,but note that they are not ready replacements for other examples.
You may want to think why.
bamboo4
what's up with no one being misspelled twice?
Claytonain
its waiting for you to edit + correct claytonian. feel free to improve the content...