Format of copyright notice at beginning of source files

Development & Design
1

Based on a quick search, we have copyright years of 2010 (by far the most common) and most years between now and then. We also have the copyright attributed to "OpenRefine contributors" as well as individual contributors. Is there a standard format for the copyright notices at the beginning of source files? If not, would it make sense to standardize on something like "Copyright [year the file was added], OpenRefine contributors"?

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Yes, the current standard is "Copyright (c) 2026, OpenRefine contributors" followed by the text of the license as the module header. The original copyright was "Copyright 2010, Google Inc." and Google apparently still omits the "(c)" although others recommend the Unicode copyright symbol © (and we've used both upper and lower case "(C)").

We used to have module templates for the various IDEs, but I think those templates were deleted. We could restore them for IDEs in use today if it's useful.

We have a number of modules which have personal copyright statements from the original developer and that's totally fine. They should be left as is until/unless we make substantial updates, in which case we should add our copyright. Ditto historical Google copyright statements.

Most of the incorrect copyright statements come from people cloning a module and not correctly updating the header. If a significant amount of the original code remains, then the existing header should be updated with a new copyright statement, if necessary. If it's basically entirely new code, then the current header should be used and the old one removed.

One thing that we might want to consider updating is replacing the license text with an SPDX identifier for new modules (and perhaps adding it to existing modules).

SPDX-FileCopyrightText: © 2026 OpenRefine contributors
SPDX-License-Identifier: BSD-3-Clause

That helps for people attempting to do automatic license scanning, but note that none of this affects our copyright or license. All code is copyright by its author the moment it is created, whether or not it has a copyright statement.

Tom

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