(1) *
- The directory structure does not conform to the Standards Reference.
No bundle.xml was provided. Seems that what's given is one collection of the bundle.
The top level of the bundle should have only data/ directory, i.e. the other files should sit inside data/. 
Also, inventory.csv should be named collection.csv or collection_inventory.csv.

(2) *.xml
- For URLs of nasa sites, should use https instead of http, e.g.
  <?xml-model href="http://pds.nasa.gov/pds4/geom/v1/PDS4_GEOM_1B10_1700.sch"
should be
  <?xml-model href="https://pds.nasa.gov/pds4/geom/v1/PDS4_GEOM_1B10_1700.sch"
and
  xsi:schemaLocation="http://pds.nasa.gov/pds4/pds/v1 http://pds.nasa.gov/pds4/pds/v1/PDS4_PDS_1B10.xsd
should be
  xsi:schemaLocation="http://pds.nasa.gov/pds4/pds/v1 https://pds.nasa.gov/pds4/pds/v1/PDS4_PDS_1B10.xsd

(3) spectrum1d/*.xml
- Every file has the following
  <local_identifier_reference>spectrum</local_identifier_reference>
  <local_reference_type>spectral_characteristics_to_table_object</local_reference_type>
  ...
  <Table_Delimited>
    <local_identifier>spectrum</local_identifier>
Schematron PDS4_SP_1B00_1100.sch (of the local data dictionary) requires Table_Character or Table_Binary, and not Table_Delimited.
Either these files or the schematron should change.

(4) spectrum1d/*.xml
- Need to change the nonconforming target LIDs in lid_references  since the LID formation rule for comets are:
 a) removes '/' after the initial letter in the designation rather than replacing with '_',
 b) allows '-'. 

The LIDs below in the first column are the target LIDs used in the collection minus prefix urn:nasa:pds:context:target.
If listed, the LIDs in the second column are the LIDs should be used.
* indicates that the LID or the changed LID has already been registered.
  comet.6p_d_arrest
  comet.8p_tuttle*
  comet.9p_tempel_1*
  comet.17p_holmes*
  comet.21p_giacobini_zinner         comet.21p_giacobini-zinner*
  comet.29p_schwassmann_wachmann_1   comet.29p_schwassmann-wachmann_1*
  comet.37p_forbes*
  comet.41p_tuttle_giacobini_kresak  comet.41p_tuttle-giacobini-kresak
  comet.46p_wirtanen*
  comet.48p_johnson
  comet.62p_tsuchinshan_1
  comet.65p_gunn
  comet.67p_churyumov_gerasimenko    comet.67p_churyumov-gerasimenko*
  comet.71p_clark*
  comet.73p_schwassmann_wachmann_3_b comet.73p_schwassmann-wachmann_3-b
  comet.73p_schwassmann_wachmann_3_c comet.73p_schwassmann-wachmann_3-c
  comet.78p_gehrels_2
  comet.88p_howell
  comet.105p_singer_brewster
  comet.121p_shoemaker_holt_2        comet.121p_shoemaker-holt_2
  comet.123p_west_hartley            comet.123p_west-hartley
  comet.132p_helin_roman_alu_2       comet.132p_helin-roman-alu_2
  comet.144p_kushida*
  comet.c_2001_q4_neat               comet.c2001_q4_neat*
  comet.c_2003_k4_linear             comet.c2003_k4_linear
  comet.c_2003_t3_tabur              comet.c2003_t3_tabur
  comet.c_2003_t4_linear             comet.c2003_t4_linear
  comet.c_2004_b1_linear             comet.c2004_b1_linear
  comet.c_2004_q2_machholz           comet.c2004_q2_machholz
  comet.c_2006_p1_mcnaught           comet.c2006_p1_mcnaught
  comet.c_2006_q1_mcnaught           comet.c2006_q1_mcnaught
  comet.c_2007_n3_lulin              comet.c2007_n3_lulin
  comet.c_2008_t2_cardinal comet.c_2008_t2_cardinal
Note that EN will need to create a context product for any row not ending in *. 
For the rows with a second column, SBN needs to change the LID.
Please inform EN if the LID changes are acceptable and if the collection
will be available so that EN can create the context products.


(5) spectrum1d/41P_Tuttle_Giacobini_Kresak-pre1.275-20060418.09-irs.xml
- <title> has a non IsBasicLatin character in Kresák:
  <title>Spitzer/IRS spectrum of comet 41P/Tuttle-Giacobini-Kresák at 1.275 AU ...
Please replace the character by "a".