Revise filters.md to clarify
@@ -42,19 +42,22 @@ for previously working code because of these reversions. In that case,
please revise your code to adhere to this document. Apologies are extended
for any inconvenience.
-The primary user-visible incompatibiltities are as follows:
-* Some functions (e.g. nc_inq_var_filter_ids) had a different name
-in the previous releases.
-* The functions _nc_inq_var_filter_info_ and nc_inq_var_filter return the _NC_ENOFILTER_ error when information
-is requested about from a variable that has no filters or does not have a specified filter attached.
+A user may encounter an incompatibility if any of the following
+appears in user code.
+
+* The function _nc_inq_var_filter_ was returning the error value _NC_ENOFILTER_
+ if a variable had no associated filters. It has been reverted to the previous
+ case where it returned _NC_NOERR_ and the returned filter id was set to zero
+ if the variable had no filters.
+* The function _nc_inq_var_filterids_ was renamed to _nc_inq_var_filter_ids_.
* Some auxilliary functions for parsing textual filter specifications
have been moved to __netcdf_aux.h__. See <a href="#filters_appendixa">Appendix A</a>.
-* It is no longer possible to use a filter name, such as "szip";
-one must use the assigned filter id, 4 for szip.
+* All of the "filterx" functions have been removed. This is
+ unlikely to cause problems because they had limited
+ visibility.
For additional information, see <a href="#filters_appendixb">Appendix B</a>.
-
# Enabling A HDF5 Compression Filter {#filters_enable}
HDF5 supports dynamic loading of compression filters using the following
