There are a couple of keywords in CND files which are reminiscent of JSR 170 and Jackrabbit's notation, which don't comply with JSR-283:

1) MULTIPLE
The following:

[inf:withsnschild] 
    + * (inf:childnode1) IGNORE MULTIPLE

is accepted by modeshape and acts as if it were defined as

[inf:withsnschild] 
    + * (inf:childnode1) IGNORE SNS

This should not be supported and ModeShape should raise an explicit exception. The eclipse cnd editor plugin correctly doesn't support the MULTIPLE attribute on child node definitions, only on properties.

2) PRIMARY
The following definitions:

[nt:file] > nt:hierarchyNode 
  + jcr:content (nt:base) primary mandatory

[nt:linkedFile] > nt:hierarchyNode 
  - jcr:content (reference) primary mandatory

should really be:

[nt:file] > nt:hierarchyNode primaryitem jcr:content
+ jcr:content (nt:base) mandatory

[nt:linkedFile] > nt:hierarchyNode primaryitem jcr:content
- jcr:content (REFERENCE) mandatory

The PRIMARY keyword should not be supported (neither on properties, nor on children) and an appropriate exception should be thrown.

Also, the node.getPrimaryItem() method implementation should make sure it supports both nodes and properties alike.