Clean up doxygen warnings that were being treated as failures.

docs/dispatch.md

@@ -520,7 +520,7 @@ Modifying the dispatch version requires two steps:
 
 The two should agree in value.
 
-### NC_DISPATCH_VERSION Incompatibility
+## NC_DISPATCH_VERSION Incompatibility
 
 When dynamically adding a dispatch table
 -- in nc_def_user_format (see libdispatch/dfile.c) --

docs/filters.md

@@ -65,6 +65,28 @@ The concept of a variable-sized type is defined as follows:
    then that compound type is variable-sized.
 4. All other types are fixed-size.
 
+## A Warning on Backward Compatibility {#filters_compatibility}
+
+The API defined in this document should accurately reflect the
+current state of filters in the netCDF-c library.  Be aware that
+there was a short period in which the filter code was undergoing
+some revision and extension.  Those extensions have largely been
+reverted.  Unfortunately, some users may experience some
+compilation problems 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.
+
+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 returns 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 the file *netcdf\_aux.h*. See [Appendix A](#filters_appendixa).
+* All of the "filterx" functions have been removed. This is unlikely to cause problems because they had limited visibility.
+
+For additional information, see [Appendix B](#filters_appendixb).
+
 ## Enabling A HDF5 Compression Filter {#filters_enable}
 
 HDF5 supports dynamic loading of compression filters using the

docs/internal.md

@@ -8,13 +8,13 @@ This document attempts to record important information about
 the internal architecture and operation of the netcdf-c library.
 It covers the following issues.
 
-* [Including C++ Code in the netcdf-c Library](#intern_c++)
+* [Including C++ Code in the netcdf-c Library](#intern_cpp)
 * [Managing instances of variable-length data types](#intern_vlens)
 * [Inferring File Types](#intern_infer)
 * [Adding a Standard Filter](#intern_filters)
 * [Test Interference](#intern_isolation)
 
-# 1. Including C++ Code in the netcdf-c Library {#intern_c++}
+# 1. Including C++ Code in the netcdf-c Library {#intern_cpp}
 
 The state of C compiler technology has reached the point where
 it is possible to include C++ code into the netcdf-c library

docs/nczarr.md

@@ -449,16 +449,16 @@ Here are a couple of examples using the _ncgen_ and _ncdump_ utilities.
     ```
 4. Create an nczarr file using S3 as storage and keeping to the pure zarr format.
     ```
-    ncgen -4 -lb -o "s3://s3.uswest-1.amazonaws.com/datasetbucket#mode=zarr" dataset.cdl
+    ncgen -4 -lb -o 's3://s3.uswest-1.amazonaws.com/datasetbucket#mode=zarr dataset.cdl
     ```
 5. Create an nczarr file using the s3 protocol with a specific profile
     ```
-    ncgen -4 -lb -o "s3://datasetbucket/rootkey#mode=nczarr,awsprofile=unidata" dataset.cdl
+    ncgen -4 -lb -o 's3://datasetbucket/rootkey#mode=nczarr,awsprofile=unidata' dataset.cdl
     ```
     Note that the URL is internally translated to this
-    ````
-    https://s2.<region&gt.amazonaws.com/datasetbucket/rootkey#mode=nczarr,awsprofile=unidata" dataset.cdl
-    ````
+    ```
+    'https://s2.<region&gt.amazonaws.com/datasetbucket/rootkey#mode=nczarr,awsprofile=unidata' dataset.cdl
+    ```
 
 # References {#nczarr_bib}
 
@@ -473,7 +473,7 @@ collections — High-performance dataset datatypes](https://docs.python.org/2/li
 <a name="dynamic_filter_loading">[8]</a> [Dynamic Filter Loading](https://support.hdfgroup.org/HDF5/doc/Advanced/DynamicallyLoadedFilters/HDF5DynamicallyLoadedFilters.pdf)<br>
 <a name="official_hdf5_filters">[9]</a> [Officially Registered Custom HDF5 Filters](https://portal.hdfgroup.org/display/support/Registered+Filter+Plugins)<br>
 <a name="blosc-c-impl">[10]</a> [C-Blosc Compressor Implementation](https://github.com/Blosc/c-blosc)<br>
-<a name="ref_awssdk_conda">[11]</a> [Conda-forge / packages / aws-sdk-cpp](https://anaconda.org/conda-forge/aws-sdk-cpp)<br>
+<a name="ref_awssdk_conda">[11]</a> [Conda-forge packages / aws-sdk-cpp](https://anaconda.org/conda-forge/aws-sdk-cpp)<br>
 <a name="ref_gdal">[12]</a> [GDAL Zarr](https://gdal.org/drivers/raster/zarr.html)<br>
 
 # Appendix A. Building NCZarr Support {#nczarr_build}
@@ -539,7 +539,7 @@ PATH="$PATH:${AWSSDKBIN}"
 Then the following options must be specified for cmake.
 ````
 -DAWSSDK_ROOT_DIR=${AWSSDK_ROOT_DIR}
--DAWSSDK_DIR=${AWSSDK_ROOT_DIR}/lib/cmake/AWSSDK"
+-DAWSSDK_DIR=${AWSSDK_ROOT_DIR}/lib/cmake/AWSSDK
 ````
 # Appendix B. Amazon S3 Imposed Limits {#nczarr_s3limits}
 
@@ -578,7 +578,7 @@ can in fact be any legal JSON expression.
 This "convention" is currently used routinely to help support various
 attributes created by other packages where the attribute is a
 complex JSON expression.  An example is the GDAL Driver
-convention <a href="#ref_gdal">[12]</a>, where the value is a complex
+convention <a href='#ref_gdal'>[12]</a>, where the value is a complex
 JSON dictionary.
 
 In order for NCZarr to be as consistent as possible with Zarr Version 2,