According to the specification in /nfs/users/nfs_s/ss34/annot/skel/misc/new_gff_format.lua,

a contig feature
  - appears as a root node (2288 success/es)
  - should not have children (2288 success/es)
  - only contains allowed attributes (2288 success/es)
a CDS feature
  - should not have children (8933 success/es)
  - appears as child of an mRNA (8933 success/es)
  - only contains allowed attributes (8933 success/es)
a gap feature
  - appears as a root node (1839 success/es)
  - should not have children (1839 success/es)
  - only contains allowed attributes (1839 success/es)
a snoRNA feature
  - only contains allowed attributes (3 success/es)
  - should not have children (3 success/es)
  - appears as part of a gene (3 success/es)
a tRNA feature
  - only contains allowed attributes (96 success/es)
  - should not have children (96 success/es)
  - appears as part of a gene (96 success/es)
a snRNA feature
  - only contains allowed attributes (3 success/es)
  - should not have children (3 success/es)
  - appears as part of a gene (3 success/es)
a rRNA feature
  - only contains allowed attributes (12 success/es)
  - should not have children (12 success/es)
  - appears as part of a gene (12 success/es)
a gene feature
  - only contains allowed attributes (8938 success/es)
  - has consistent strands across all children (8938 success/es)
  - has only allowed child types (8938 success/es)
  - appears as a root node (8938 success/es)
  - contains all child features within its coordinates (8938 success/es)
a mRNA feature
  - agrees exactly with CDS/UTR coordinates of its children (8824 success/es)
  - only contains allowed attributes (8824 success/es)
  - has a coding sequence >= 3bp (8824 success/es)
  - has at least one CDS child (8824 success/es)
  - has only allowed child types (8824 success/es)
  - has non-partial CDS ending on a stop codon (8554 success/es)
  - has non-selenocysteine CDS with no internal stop codons (8824 success/es)
  - consists of less than 50% Ns (8824 success/es)
  - appears as part of a gene (8824 success/es)
a polypeptide feature
  - agrees exactly with CDS of >=1 overlapping coding transcripts (8824 success/es)
  - only contains allowed attributes (8824 success/es)
  - has a required product attribute (8824 success/es)
  - overlaps the transcript it derives_from (8824 success/es)
  - must be derived_from a unique mRNA (8824 success/es)
  - appears as a root node (8824 success/es)

Encountered 0 parser warning/s.

Traversed 22337 CCs (10 feature types), checked 216302 nodes for 41 aspects.
Finished in 8.408376 s.