codepill

Code pill

A licensing scheme for humans and machines — specification version 1

What are code pills?

There are numerous licensing terms for code and data, all different from one another. It is hard for a human to understand all the subtleties of these licensing terms, and even harder for a machine to follow and respect them.

Code pills are small capsules that apply to code, generic data, a document, a part of a document, a part of a speech, or a part of a sentence.

A pill is written as an opening tag such as (1ACM] and, when needed, a matching closing tag such as [1ACM). The letters inside the pill (here A, C and M) tell what the author asks in exchange for using the tagged content.

The principle fits in one sentence:

A pill grants every right the author can legally grant. Each letter in the pill takes some freedom back.

So (1] (an empty pill) means “do what you want with it”, (1A] means “do what you want, but credit me”, and (1ACM] means “credit me, no commercial use, no machine processing”.

You can embed pills in comments of textual data formats, in the header of the data (if any), in the metadata section of a media file (such as EXIF comments), in the file name when it is visible, or say them aloud in a speech.

Definitions

The key words “MUST”, “MUST NOT”, “SHOULD”, “SHOULD NOT” and “MAY” are to be interpreted as described in RFC 2119.

Pill: an opening tag, optionally followed later by its closing tag, as defined in the Syntax section.

Scope: the content a pill applies to, excluding the pill tags themselves.

• A pill found in the header or in the metadata of a document (such as the file name or a specific metadata section of a file) applies to the whole document: the scope is the document content.
• A pill tagging some data within the document applies to the tagged data, from the opening tag to its closing tag (or to the end of the document if there is no closing tag).
• Several scopes can exist in a document, and scopes can be nested.

Author: the author (or rights holder) of the scope.

User: anyone, human or organisation, who uses the scope in any way, including through an automated process they run or commission.

Distribution channel: the medium used by the author to distribute or publish the document. It can be (but is not limited to): a code repository, a written document, a website, a media file, or a public or private speech. The distribution channel does not need to be publicly available: the same terms apply to a document whether it was acquired legally or illegally, privately or publicly.

Effective letters: the set of letters that applies to a given part of a document, once all enclosing pills are taken into account (see Nesting).

Applicable law: the copyright and authors’ rights law that applies to the use, including its statutory exceptions (such as quotation) and the author’s moral rights.

Relationship with the law

• No pill: when no pill is found, this specification does not apply. The content is protected by the applicable law, which, in nearly every country (Berne Convention), means all rights reserved.
• Empty pill: (1] grants every economic right the author is legally able to grant. Rights the author cannot give away under the applicable law (for example, inalienable moral rights such as the right to integrity in France) remain with the author. The term “public domain” is deliberately not used, since it has different meanings in different countries.
• Letters: each letter is a condition attached to that grant. A user who does not respect a condition is not granted any right by the pill over the scope: the use is then governed by the applicable law alone.
• Statutory exceptions: a pill cannot remove a right that the applicable law gives to everyone (such as the right of quotation or fair use). Letters restrict what the pill grants, not what the law allows.
• Other licences: a document can also be distributed under another licence. Each licence is an independent grant and this specification does not combine with others. Authors SHOULD avoid contradictory statements.

Syntax

opening  = "(" [ version ] letters [ "~" id ] "]"
closing  = "[" [ version ] letters [ "~" id ] ")"
version  = 1*DIGIT                          ; "1" for this specification
letters  = *ALPHA                           ; see "Pill letters" for their meaning
id       = 1*( ALPHA / DIGIT / "-" / "_" / "." )

Examples: (1A], (1ACM~photos], (1], (m], [1ACM~photos).

• The pill only uses characters that are valid in file names on common systems (no :, |, !, /…), so it can appear in a file name as is.
• The version is the number at the start of the pill: (1ACM] is version 1 with the letters A, C and M. The empty pill of version 1 is (1].
• The outermost pill of a document MUST carry the version. Pills nested inside a versioned scope MAY omit it: they inherit it. Tools SHOULD NOT treat an unversioned pill as a pill unless it is inside a versioned scope, to avoid confusion with ordinary text.
• A pill is interpreted with the meaning its version gives to each letter. Letters that this version does not define are ignored: since the version is part of the pill, a new letter introduced by a later version cannot be confused with a mistake.
• A processor that does not know the version of a pill MUST interpret the whole document as if its only pill were (N]: no use is granted except proving authenticity, date or authorship.
• The scope name uses ~ because it is valid in file names and in URLs, where # would start a fragment and @ has a special meaning.
• The order of letters is irrelevant. Repeating a letter has no additional effect.
• The optional ~id names the scope, so that its terms can be found in the PILL_TERMS.txt file (see PILL_TERMS.txt).
• A closing tag MUST repeat exactly the content of the opening tag it closes, and closes the innermost open scope. It releases the letters that this opening tag added.
• A pill covering a whole document does not need a closing tag. A closing tag becomes functionally required as soon as the document may be included in another one (for example, a C header file included in another source file, or a paragraph pasted in another text).
• A closing tag that does not match the innermost open pill is ignored: the open pill keeps applying, up to the end of the document if needed.
• In a speech, the speaker says the pill aloud (for example “code pill one, A C M”) at the beginning of the scope, and announces its end if the scope ends before the speech does. In a video, the pill MAY instead be displayed visibly for the whole scope (on screen, on a badge…).

Pill letters

All letters apply to the complete scope. Uppercase letters take a freedom back. Lowercase letters are only meaningful in a nested pill, where they give back a freedom that an enclosing pill took (see Nesting).

Letter	Name	What it takes back
A	Attribution	Using the scope without crediting the author.
C	No commercial use	Any commercial use.
D	Distinct works only	Reusing the scope, or recognizable parts of it, in another work.
F	Feedback for commercial use	Commercial use without a prior agreement with the author on retribution.
M	No machine use	Automated processing that is not for immediate human consumption.
N	No use (proof only)	Every use, except proving the authenticity, date or authorship of the scope.
P	Poison	Every use, including attribution: the scope is disowned and must be treated as noise.
R	No modification	Modifying the scope: only verbatim copies are allowed.
S	Share alike	Distributing a work based on the scope under any other terms than the very same pill.
T	Truthful quotation	Quoting the scope partially, without credit, or in a way that alters its meaning.
W	Warranty (informative)	Nothing: it signals that specific warranty terms apply.

A: Attribution

Any work including the scope or part of the scope MUST include a textual, audio, or visual element containing the name of the author.

The name to use is given by an Author: field, in the document’s header, in the file metadata, or in the PILL_TERMS.txt file of the distribution channel. Multiple Author: fields are allowed. If a third party is acting on behalf of the author, its name and contact information MAY be given in an Agent: field. The author cannot claim a failure in attribution if the name is not found explicitly in one of these places. A means of contacting the author (an email address, a website…) is recommended but not mandatory, using a Contact: field.

C: No commercial use

The scope MUST NOT be used commercially: it MUST NOT be sold, included in a product or service that is sold or that generates revenue (including through advertising), or used in the course of a for-profit activity.

If both C and F are present, C wins: no commercial use is granted.

D: Distinct works only

The scope MUST NOT be reused as is, nor included in a larger work, nor reused through recognizable parts of it. A user MAY create a new work inspired by the scope, provided it is transformed so much that there is no possible doubt that it is not the original work.

Copying and distributing the scope itself, unchanged and on its own, remains allowed unless other letters say otherwise.

For example, if the scope is a song: sharing the song is allowed; composing a new song whose inspiration cannot be recognized is allowed; using the song (or a recognizable sample of it) in a remix, a movie soundtrack, or an advertisement is not.

F: Feedback for commercial use

Commercial use of the scope is only granted once the user and the author have concluded an agreement on how the value brought by the scope is returned to the author.

The rationale is simple: if a user builds a commercial activity on the scope, it is because the scope has value, and the author deserves to discuss how that value is shared. Without such an agreement, no commercial right is granted.

The author MAY describe what is expected in a Feedback: field of the PILL_TERMS.txt file, as a starting point for the discussion. For example, and not limited to:

• a share of the revenue directly or indirectly generated, proportional to the importance of the scope in the user’s product or service (for software, the ratio of active code coming from the scope in the final product is a possible estimate);
• maintenance or development work on the scope, in time proportional to that importance;
• a one-time payment, a donation, or any other form of return.

If the author cannot be reached, no agreement can be concluded and no commercial right is granted. Authors using F SHOULD therefore provide a Contact: field.

F does not require the user to publish modifications. If the author wants that too, the pill also contains S.

M: No machine use

The following uses of the scope are forbidden: data extraction, machine-learning training, text and data mining, any processing that is not targeted at immediate human consumption, and any processing not intended by the author.

Are not concerned, because they only convey the scope to a human as intended: displaying, rendering, printing, transmitting, storing or backing up the scope, accessibility tools (such as a screen reader), and, for code, compiling and executing it.

For users subject to European Union law, M is a machine-readable reservation of rights in the sense of Article 4(3) of Directive (EU) 2019/790 (text and data mining opt-out).

N: No use (proof only)

No use of the scope is granted, whatever the purpose: no copy, distribution, communication, quotation, modification, processing or derivative work.

The only exception is proving the authenticity of the scope: the scope MAY be kept, timestamped, fingerprinted (for example with a cryptographic hash), and presented to establish its existence, its date, or its authorship, for example to prove the anteriority of an invention.

Unlike P, the author fully claims the scope as their own work.

P: Poison

The scope is disowned by the author: it is noise, decoy, or generated content that the author does not claim. It MUST be treated as if it were empty or non-existent: no copy, distribution, quotation, modification, processing or use of any kind is granted, and the scope MUST NOT be attributed to the author nor used as an expression of their work or opinions.

P exists for forensic purposes: since nobody is allowed to use a poisoned scope, finding it, or something recognizably derived from it, anywhere else (in another document, in a dataset, in the output of a model) proves that the pill was not respected.

P dominates every other letter.

R: No modification

The scope MUST NOT be modified. Copying and distributing verbatim copies of the scope is allowed unless other letters say otherwise. Changing the format without changing the content (for example, re-encoding an image) is not a modification.

S: Share alike

Any work that includes or is based on the scope, when distributed, MUST be distributed under a pill with exactly the same letters as the scope’s pill.

T: Truthful quotation

Any partial reuse (quotation, excerpt) of the scope MUST:

• name the author and the source;
• be clearly identifiable as a quotation;
• not alter, distort or reverse the meaning of the scope, including by cutting it.

If the meaning of the scope depends on its whole, only the complete scope can be reused. For example, if the scope is a political pamphlet, an excerpt that makes it say something the complete pamphlet does not say is forbidden.

T strengthens, in the pill, the rules that most laws already attach to quotation (for example the French droit de citation and the author’s right to the integrity of the work).

W: Warranty

By default, without this letter, no warranty is given and no damage claim is accepted arising from the use of the scope. If W is present, specific warranty or damage terms apply, described in a Warranty: field of the PILL_TERMS.txt file.

W does not take any freedom back: it is informative.

Nesting

Pills can be nested. The effective letters of a nested scope are the effective letters of its enclosing scope, plus its uppercase letters, minus its lowercase letters.

(1ACM]               effective: A C M
  ...
  (m]                effective: A C      (machines may process this part)
    ...
    (R]              effective: A C R
    [R)              effective: A C
  [m)                effective: A C M
  ...

Only the author of a scope MAY add a pill inside it, and therefore only the author can relax a letter with a lowercase letter. A third party MUST NOT remove, modify, add to, or alter a pill.

A lowercase letter is a convenience: it avoids closing a pill, then opening it again, around the narrower part.

Using pilled content

• Pills are non-removable. Any copy, excerpt, or work that includes or is based on a scope MUST carry the scope’s pill (with its closing tag when included in a larger work).
• Letters add up. When contents from several scopes are combined, the result carries all their pills, and the effective letters of the result are the union of their letters.
• The most restrictive wins. When two letters cannot both be satisfied, the one granting less applies: P dominates everything, then N, and C dominates F.
• Incompatible combinations are forbidden. Contents cannot be combined when their pills cannot all be respected together. In particular:
  • a scope with N or P cannot be combined with anything;
  • a scope with D cannot be included, recognizably, in a combination;
  • a scope with S can only be combined with scopes whose letters are all present in its own pill, and two S scopes can only be combined if they have exactly the same letters.
• Generated content. Content generated by a process that used pilled scopes (for example, a model trained on them) is a work based on those scopes: it MUST carry the combination of their pills. If the combination is incompatible, the output MUST be discarded. In practice, this means training datasets have to be separated into groups of compatible pills.

PILL_TERMS.txt

The PILL_TERMS.txt file is a UTF-8 text file placed at the root of the distribution channel (for example, at the root of a code repository or a website). It holds the information some letters refer to.

• The file is made of records separated by an empty line.
• Each record is made of Field: value lines. A value can continue on the next lines, which then start with a space or a tab.
• A record starting with Scope: <id> applies to the pills with that ~id. A record without a Scope: field applies to the pills without an ~id.

Field	Used by	Content
Scope:	all	The ~id of the pills this record applies to.
Author:	A	The name to credit. Can be repeated for multiple authors.
Agent:	A, F	A third party acting on behalf of the author, with its contact.
Contact:	A, F	A way to contact the author.
Feedback:	F	What the author expects in exchange for commercial use.
Warranty:	W	The warranty and/or damage terms.

Example:

Author: Jane Doe
Contact: jane@example.org

Scope: engine
Author: Jane Doe
Author: John Roe
Contact: engine@example.org
Feedback: 2% of the net revenue of any product shipping this engine,
  or equivalent maintenance time. Please contact us before shipping.

Scope: icons
Author: Studio Example
Warranty: The icons are guaranteed free of any third-party rights.
  The author covers documented claims up to 1000 EUR.

FAQ

Why does a pill grant everything by default, instead of reserving everything? Because the law already reserves everything when there is no pill. A pill is only useful to give rights away, and the most common wishes are then the shortest to write: (1A] for “credit me”, (1AS] for “credit me and keep it open”, (1ACM] for “credit me, not for profit, not for machines”.

Do I need a closing pill? Not for a whole document. You need one as soon as the protection changes inside a document, or when the document may be included in another one.

How do I lift a restriction for a small part of my document? Use a nested pill with the lowercase letter, such as (m] inside a (1ACM] document. You can also close the pill and open a new one.

What happens with an unknown letter? It is ignored. The pill carries its version, so a letter added by a later version is read with that version’s specification, and a letter that no version defines has no meaning.

What happens with a version I don’t know? The whole document is read as N: nothing is granted until the tool knows that version. This way, a tool that is not up to date never grants a freedom that a newer letter takes back.

Why a number and not CP1: as a prefix? A pill must survive in a file name. : is forbidden in Windows file names, and | or ! are special characters in POSIX shells. A leading digit is valid everywhere and keeps the pill short: (1ACM].

What is the difference between N and P? With N, the author claims the work but keeps it private: it can only be used as proof of its existence, date, or authorship. With P, the author disowns the content: it is noise that must be ignored, and finding it anywhere else proves the pills were not respected.

Can a pill forbid me to quote a text? No. The right of quotation granted by law (fair use, fair dealing, droit de citation…) is not given by the pill, so it cannot be taken back by the pill. T only makes the rules of a faithful quotation explicit.

How do I put a pill in a speech or a video? Say it aloud when the scope starts (and when it ends if it ends before the speech does), or display it visibly for the whole scope.