MSI Plessey — format provenance and usability
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This file records where the MSI Plessey symbology comes from, what governs
it, and the basis on which this project implements and redistributes it.

It is an ENGINEERING INVENTORY, NOT LEGAL ADVICE. Items marked [TO VERIFY]
have not been independently confirmed by the author.


ORIGIN
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A variant of the Plessey Code, developed by the MSI Data Corporation.
[LEGAL REVIEW] Chiefly used for retail shelf labelling and inventory.


SPECIFICATION
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No ISO/IEC standard exists for MSI. It is documented through
vendor and industry publications rather than a formal standard. [LEGAL
REVIEW]

Specification TEXT is copyrighted by its publisher. The SYMBOLOGY it
describes is not — an encoding scheme is a system, not a work of
authorship. This project implements the symbology; it does not reproduce,
redistribute or excerpt any specification document.


PATENT STATUS
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The originating patents date from the 1970s and are understood to have
expired. [LEGAL REVIEW]


TRADEMARK
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No live trademark restriction on implementing MSI is known to the author.
[LEGAL REVIEW] That is a statement about the author's knowledge, not a
finding that no mark subsists: no trademark search was carried out. MSI
Data Corporation is understood no longer to exist as an independent
entity. [LEGAL REVIEW]

A trademark does not restrict implementing a symbology. It restricts
branding — how a product names and presents itself.


IMPLEMENTATION BASIS IN THIS PROJECT
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MSI Plessey is implemented here from published descriptions of the format,
which are systems and facts rather than works of authorship. No source
code or constant table from any other barcode implementation is copied or
shipped. Public technical material and independent implementations may be
consulted for engineering review or black-box verification; provenance is
recorded in NOTICE.md.


CONCLUSION
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On the basis of the references below, MSI Plessey is understood to be freely
implementable and redistributable, and this project's implementation of it
is distributed under the MIT License with no additional restriction.

References relied upon:
  - Published descriptions of the MSI and Plessey symbologies [LEGAL REVIEW]

This is an engineering assessment, not legal advice. Items marked
[TO VERIFY] have not been independently confirmed by the author. If your
use is commercially sensitive, obtain your own legal review.