A development environment tracks code sections which have been copied and pasted into a code module from a source code section which has not been subjected to certain verifications. In one aspect, if an error in a copied section is later found during a verification process, the programmer is allowed to perform a multi-edit operation, whereby an edited change to a single copy is automatically propagated to multiple copies. In another aspect, the programmer is warned when copying and pasting a code section which has not been verified. Preferably, verification is performed in the process of compiling source into executable object code.