Accession passport data basics updated

src/main/asciidoc/sections/accedoc.adoc

@@ -71,7 +71,7 @@ collecting and collector information.
 ==== Breeders material
 
 Lines developed by breeding programs of the institute may be included the collection. Information provided by the breeders
-should include the pedigree, ancestral information of the material, along with names and identifiers used by the breeding
+should include the pedigree or ancestral information (selection history) of the material, along with names and identifiers used by the breeding
 program and the codes and names of institutes that developed the material.
 
 [[accedoc-acq]]
@@ -80,7 +80,8 @@ program and the codes and names of institutes that developed the material.
 Material coming from other institutes and genebanks must be accompanied by accession passport data
 as documented in the source genebank.
 
-NOTE: *Country of origin* is the country where the material was collected or bred, not the country of source genebank.
+NOTE: *Country of origin* is the country where the material was collected or bred, not the country of 
+the source genebank.
 
 Accession documentation should capture any identifiers provided by the source institute. This data
 allows for validation and curation of passport data between the genebanks and allows researchers

src/main/asciidoc/sections/mcpd.adoc

@@ -2,13 +2,14 @@
 
 == Multi-Crop Passport Descriptors
 
-The http://www.bioversityinternational.org/e-library/publications/detail/faobioversity-multi-crop-passport-descriptors-v2-mcpd-v2/[Multi-crop Passport Descriptors (MCPD V.2)]
-is a revision of the original FAO/IPGRI publication released in 2001, 
+The http://www.bioversityinternational.org/e-library/publications/detail/faobioversity-multi-crop-passport-descriptors-v21-mcpd-v21/[Multi-crop Passport Descriptors (MCPD V.2.1)]
+is an update to MCPD V.2 which was released in 2012. The MCPD V.2 was a revision of 
+the first FAO/IPGRI publication released in 2001, 
 expanded to accommodate emerging needs, such as the broader use of GPS tools, or the 
 implementation of the http://www.planttreaty.org[International Treaty on Plant Genetic Resources for 
 Food and Agriculture] Multilateral System for access and benefit sharing. 
 
-This MCPD V.2 list is an expansion of the first version of the MCPD, the descriptors and allowed values of the first 
+This MCPD V.2.1 list is an expansion of the first version of the MCPD, the descriptors and allowed values of the first 
 version form a subset of those in this revision. The 2001 list, developed jointly by 
 http://www.bioversityinternational.org[Bioversity International] (formerly IPGRI) and FAO,
 has been widely used and is considered the international standard to facilitate germplasm passport 
@@ -32,6 +33,10 @@ consistent manner.
 |Field name
 |Description
 
+|<<puid,PUID>>|Any persistent, unique identifier assigned to the accession so it can be unambiguously 
+	referenced at the global level and the information associated with it harvested through automated
+	means. Report one PUID for each accession.
+ 
 |<<mcpd-wiews,INSTCODE>>|FAO WIEWS code of the institute where the accession is maintained.
 |ACCENUMB|Unique identifier of the accession within a genebank.
 |COLLNUMB|Original identifier assigned by the collector(s) of the sample, normally composed of the 
@@ -119,6 +124,38 @@ consistent manner.
 |REMARKS|The remarks field is used to add notes or to elaborate on descriptors with value `99` or `999` (= Other). Prefix remarks with the field name they refer to and a colon (:) without space (e.g. `COLLSRC:riverside`). Distinct remarks referring to different fields are separated by semicolon without space.
 |===
 
+[[puid]]
+==== Persistent unique identifier
+
+Any persistent, unique identifier assigned to the accession so it can be unambiguously 
+referenced at the global level and the information associated with it harvested through 
+automated means. Report one PUID for each accession.
+
+There are various "types" of PUIDs: DOI, UUID, LSID, etc.
+
+The Secretariat of the ITPGRFA is facilitating the assignment of 
+DOI to PGRFA at the accession level (http://www.planttreaty.org/doi).
+
+UUID (https://en.wikipedia.org/wiki/Universally_unique_identifier[Universally unique identifier])
+is an identifier standard used in software. A UUID is simply a 128-bit value (16 bytes).
+
+For human-readable display, many systems use a canonical format using hexadecimal text with
+inserted hyphen characters. For example:
+
+	de305d54-75b4-431b-adb2-eb6b9e546014
+
+The intent of UUIDs is to enable distributed systems to uniquely identify information *without significant central coordination*. 
+In this context the word unique should be taken to mean "practically unique" rather than "guaranteed unique".
+
+Different https://en.wikipedia.org/wiki/Universally_unique_identifier#Variants_and_Versions[variants and versions of UUID] exist.
+Version 4 (Random UUID) is most commonly used in software.
+
+Genebanks not applying a true PUID to their accessions should use, and request recipients to 
+use, the concatenation of INSTCODE, ACCENUMB, and GENUS as a globally unique identifier 
+similar in most respects to the PUID whenever they exchange information on accessions with 
+third parties (e.g. `NOR017:NGB17773:ALLIUM`).
+
+
 [[mcpd-wiews]]
 ==== Institute codes in MCPD