make identification topiccategory, fees, accessconstraints, maintenan…

…cefrequency optional (#242)

docs/content/reference/mcf.md

@@ -141,13 +141,13 @@ charset|Optional|full name of the character coding standard used for the dataset
 title|Mandatory|name by which the cited resource is known|Important Bird Areas|ISO 19115:2003 Section B.3.2.1
 edition|Optional|version of the cited resource|1.8.0|ISO 19115:2003 Section B.3.2.1
 abstract|Mandatory|brief narrative summary of the content of the resource(s)|Birds in important areas...|ISO 19115:2003 Section B.2.2.1
-topiccategory|Mandatory|main theme(s) of the dataset (must be one of 'geoscientificInformation', 'farming', 'elevation', 'utilitiesCommunication', 'oceans', 'boundaries', 'inlandWaters', 'intelligenceMilitary', 'environment', 'location', 'economy', 'planningCadastre','biota', 'health', 'imageryBaseMapsEarthCover', 'transportation', 'society', 'structure', 'climatologyMeteorologyAtmosphere'. More than one topic category can be specified|climatologyMeteorologyAtmosphere|ISO 19115:2003 Section B.5.27
-fees|Mandatory|fees and terms for retreiving the resource.  Include monetary units (as specified in ISO 4217).  If there are no fees, use the term 'None'|None,ISO 19115:2003 Section B.2.10.6
-accessconstraints|Mandatory|access constraints applied to assure the protection of privacy or intellectual property, and any special restrictions or limitations on obtaining the resource or metadata (must be one of 'patent', 'otherRestrictions','copyright','trademark', 'patentPending','restricted','license', 'intellectualPropertyRights').  If there are no accessconstraints, use the term 'otherRestrictions'|None|ISO 19115:2003 Section B.2.3
+topiccategory|Optional|main theme(s) of the dataset (must be one of 'geoscientificInformation', 'farming', 'elevation', 'utilitiesCommunication', 'oceans', 'boundaries', 'inlandWaters', 'intelligenceMilitary', 'environment', 'location', 'economy', 'planningCadastre','biota', 'health', 'imageryBaseMapsEarthCover', 'transportation', 'society', 'structure', 'climatologyMeteorologyAtmosphere'. More than one topic category can be specified|climatologyMeteorologyAtmosphere|ISO 19115:2003 Section B.5.27
+fees|Optional|fees and terms for retreiving the resource.  Include monetary units (as specified in ISO 4217).  If there are no fees, use the term 'None'|None|ISO 19115:2003 Section B.2.10.6
+accessconstraints|Optional|access constraints applied to assure the protection of privacy or intellectual property, and any special restrictions or limitations on obtaining the resource or metadata (must be one of 'patent', 'otherRestrictions','copyright','trademark', 'patentPending','restricted','license', 'intellectualPropertyRights').  If there are no accessconstraints, use the term 'otherRestrictions'|None|ISO 19115:2003 Section B.2.3
 rights|Mandatory|Information about rights held in and over the resource. pygeometa supports using the $year$ variable to update the year value at run time. |Copyright (c) 2010 Her Majesty the Queen in Right of Canada|DMCI 1.1
 url|Mandatory|URL of the dataset to which the metadata applies|http://host/path/|ISO 19115:2003 Section B.2.1
 status|Mandatory|"the status of the resource(s) (must be one of 'planned','historicalArchive','completed','onGoing', 'underDevelopment','required','obsolete')"|completed|ISO 19115:2003 Section B.2.2.1
-maintenancefrequency|Mandatory|frequency with which modifications and deletions are made to the data after it is first produced (must be one of 'continual', 'daily', 'weekly', 'fortnightly', 'monthly', 'quarterly', 'biannually', 'annually', 'asNeeded', 'irregular', 'notPlanned', 'unknown'|continual|ISO 19115:2003 B.5.18
+maintenancefrequency|Optional|frequency with which modifications and deletions are made to the data after it is first produced (must be one of 'continual', 'daily', 'weekly', 'fortnightly', 'monthly', 'quarterly', 'biannually', 'annually', 'asNeeded', 'irregular', 'notPlanned', 'unknown'|continual|ISO 19115:2003 B.5.18
 browsegraphic|Optional|graphic that provides an illustration of the dataset|http://example.org/dataset.png|ISO 19115:2003 B.2.2.2
 
 #### `identification.dates`

pygeometa/schemas/mcf/core.yaml

@@ -311,13 +311,9 @@ properties:
         required:
             - title
             - abstract
-            - topiccategory
-            - fees
-            - accessconstraints
             - rights
             - url
             - status
-            - maintenancefrequency
             - dates
             - extents
             - keywords