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- Syntactically valid MODS
- <name> if applicable (and known)
- at least one <titleInfo> element with one <title> subelement
- if known, at least one <originInfo> element with at least one <date> subelement from the recommended list, one and only one of which must be marked as a key date
- one or more <location> elements with a <url> subelement, one of which should point to the resource with its contextual material
- <accessCondition> if anything other than completely unrestricted
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- <subject>
- at least one <language> element for all resources in which language is primary to understanding the resource
- @encoding attribute on the date with the @keyDate attribute is w3cdtfOne and only one date element must be marked as a key date
- At least one <typeOfResource> using values from the approved list
- Use of access attribute on location/url, or include only one URL that points to a view of the resource in context
- At least one <physicalDescription> element with <internetMediaType> subelement; value to be taken from appropriate list
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- @type on <namePart>, when multiple <namePart> elements appear in a single <name>
- <role> subelement for <name>
- at least one <genre> element
- @encoding attribute on the date with the @keyDate attribute is w3cdtf
- <form> subelement of <physicalDescription> with @authority attribute
- More specific <subject> subelements (geographic places, etc.) over <subject>/<topic>
- @authority attribute on every <classification> element present
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