The changes in version 1.6 over version 1.5: 

General: 
- Added <status> element in Metadata (used in channel_type, synapse_type, ion_concentration currently) which can be used to indicate 
  stable/in_progress/known_issues status of files. Can be used to automatically detect unstable parts of complex models.
- Comment can be included with author info.
- Updated index.jsp to highlight 3 examples at each level as particularly useful to learn the structure of the specifications (suggestions for enhancements welcome).
- Enabled links from elements in (formatted) XML view of examples to HTML representation of XSDs (e.g. link from <meta:notes> to Metadata.xsd)
- Added Nicolas's XSDtoRNG.xsl to transform XSD files into Relax NG format


MorphML:  
- Minor changes made to position of some <text>...</text> tags in NEURON/GENESIS mapping


Biophysics: 
- Removed ReversalPotentialValue, added ConductanceDensityValue
- Moved Units element to Metadata


ChannelML:
- Allowed extra rate params (gamma, zeta) in case tau/inf need to be expressed in parameterised forms other than alpha and beta (see Kdr.xml)
- Included fixed_q10 option, when a Q10 adjustment should be included but is specified for only one temperature


NetworkML:
- num_per_source made required and max_per_target made optional in PerCellConnection, and restrictions on values updated.
- Added non_spatial_grid option to GridArrangement, to specify a grid in a network simulation where 3D location is unimportant