Each COBOL dialect has specific recommendations for compile options as well as other variables, copybook, data, routines, etc. in their own transitioning guide.
These guides are found in the Transitioning to isCOBOL documentation available at www.veryant.com.
For instance, here are some general guidelines:

Use the -cX option, where X is specific to your current COBOL vendor, to include multiple adjustments to isCOBOL to be compatible with your current applications without making code changes.

Use -ce=cpy to specify .cpy as the default file extension for copybooks.

Use -rw=word1,word2,word3 to remove reserved words. For example, -rw=PRINTER,HIGHLIGHT will remove PRINTER and HIGHLIGHT as reserved words.

Use -sp=path1;path2;path3 to specify paths to your copybooks.

If you have an environment variable such as COBCPY that contains a list of directories containing copybooks, you can add -sp=$COBCPY or -sp=%COBCPY%

If you have mixed source files in Fixed and Terminal formats, the -smat option might be necessary.

Contact Veryant Support for help determining the correct compile options and properties to use for your project.

1. Does isCOBOL support EBCDIC? How?