Conventions the chisel-releases reviewers enforce on Slice Definition Files (SDFs). These are not parse errors -- chisel accepts any well-formed slice name -- but a PR that ignores them is rejected.

Grouping

Group by content type for ordinary packages: executables, libraries, config and data. For large runtimes or packages with distinct functional subsets, use a minimum-functional core, a fuller standard, and named subsets as needed. Choose a coherent scheme per SDF and ship only functionality that can be tested. Do not include configuration for a tool that is not sliced, such as a logrotate drop-in without logrotate. Describe what a slice ships, not which application prompted its creation.

Published contents

Preserve the effective contents of published slices. When subdividing a slice, keep its original name and make it depend on the new subslices so existing consumers retain their files. Run _check-diff.py after changing published slices and verify effective contents with before/after cuts. A package leaving an archive requires archive evidence, not a failed lookup.

Canonical Slice Names

Names are convention but reviewers enforce them. The counts below are how many SDFs on ubuntu-26.04 use each name, as a rough signal of how established it is; a name is not wrong for being rare, but a rare one wants a reason.

Name	Used by	Contents
`bins`	114	Executables (plural; use `bins` not `bin`). The singular `bin` is only correct in `base-files`, whose `bin` slice builds the `/bin` and `/usr/bin` directory tree, not executables
`libs`	404	Shared libraries (plural; use `libs` not `lib`). Same `base-files` `lib` exception -- it makes the `/lib` and `/usr/lib` tree
`config`	75	Configuration files. Singular -- `configs` is not used. Break large configs into `<purpose>-config` (e.g. `modprobe-config`, `tmpfiles-config`, `pam-config`)
`scripts`	29	Shell helpers / non-binary executables. Not in `bins`
`data`	21	Static data (templates, tables, arch-independent payload). Not fonts -- those get `fonts`
`headers`	15	`/usr/include/...`. This is the name `-dev` packages use, not `dev`
`jars`	5	JVM artefacts
`copyright`	690	The deb copyright file, plus any upstream `NOTICE` / `LICENSE` / `ThirdPartyNotices` the package ships. Every SDF has one
`fonts`	15	Font files. Every font package uses this, not `data`
`core`	38	Minimum-functional subset. Not "everything". Avoid `all` -- exactly one SDF uses it (`fonts-ubuntu`, an umbrella aggregate)
`standard`	24	Fuller-featured above `core`
`var`	6	Directories/files under `/var/`
`services`	12	Systemd service files
`modules`	33	Loadable modules/plugins
`locales`	1	Translation/locale files
`tables`	1	Static data tables (`dpkg_tables` ships `/usr/share/dpkg/*table`)
`chisel`	1	The generated manifest slice; only on `base-files` (`generate: manifest`)
`udev-rules`	1	udev rules (`systemd_udev-rules` ships `/usr/lib/udev/rules.d/*.rules`). The bare name `rules` is not used
`minimal` / `runtime`	7 / 5	Alternative subset names where `core` / `standard` do not fit the package's own vocabulary

When the deb already names <pkg>-core (e.g. fonts-dejavu-core), keep the name verbatim.

There is no license or notice slice convention: upstream NOTICE, LICENSE.txt and ThirdPartyNotices.txt go inside the copyright slice next to the deb copyright file. Do not invent a separate slice for them.

Beyond this table, packages freely coin their own names for functional subsets -- openjdk ships awt, jfr, management; binutils ships assembler, linker, archiver. That is expected. The table covers the names that recur across packages; a package-specific name needs only to describe what it ships.

Path Entry Style

Conventions on how a contents: path is written. Chisel accepts either form; reviewers do not.

Multiarch lib glob: *-linux-*, not explicit triples -- /usr/lib/*-linux-*/libnghttp2.so.14*:.
Drop the trailing * for single-version sonames: libfoo.so.1:, not libfoo.so.1*:.
Version globs pin major.minor only, never the patch: /usr/src/rustc-1.93.*/**, /usr/lib/perl5/*/. A patch-level pin breaks on the next package update.
Keep globs narrow. A broad ** or a bare *.pm collides with other packages' paths. Add another path level to scope it (.../perl5/*/auto/DBI/DBI.so:). A path more than one package could own is a red flag -- grep the branch's slices/ before declaring one.
No explicit symlink: if the deb ships it. Chisel preserves the deb's own symlinks. Write symlink: only for paths the deb does not ship, e.g. ones a maintainer script creates.
Annotate explicit symlinks with a comment: /usr/bin/dotnet: # Symlink to ../lib/dotnet/dotnet.
Inline-style for short option maps: /path: {arch: [amd64, arm64]}.
Arch list order is a nit, not a gate. Alphabetical reads tidily, but real SDFs (systemd) use a priority order; do not block on it.

File Layout

Global essential: at the top of the file, right after package:.
Include <pkg>_copyright in the global essential: so every slice ships the package's legal files.
The copyright slice last in the slices: block.
package: matches the filename stem -- slices/foo.yaml -> package: foo.
One SDF per package. Never two packages in one YAML file.

Exclude by Default

A .deb ships files a minimal rootfs never needs. Do not slice these unless a concrete runtime need is proven -- reviewers reject them, and check-slice.py flags them:

Excluded	Paths	Notes
man pages	`/usr/share/man/`, `/usr/man/`	never shipped
shell completions	`/usr/share/bash-completion/`, `/usr/share/fish/`, `/usr/share/zsh/`, `/etc/bash_completion.d/`	never shipped
docs / changelogs	`/usr/share/doc/**`	except the legal files below
doc-base / lintian	`/usr/share/doc-base/`, `/usr/share/lintian/`	packaging metadata, not runtime
examples	`/usr/share/doc//examples/`, `.../example`	covered by the doc rule above

Under /usr/share/doc/<pkg>/, ship only legal files: copyright always, and the upstream legal notices (NOTICE, LICENSE, ThirdPartyNotices, with .txt/.gz variants) where the package carries them for licence compliance -- apache2, aspnetcore, and libaprutil1t64 ship NOTICE. Everything else there (README, changelog, NEWS, examples) is clutter. Shared-copyright packages instead ship /usr/share/doc/<pkg> itself as a symlink to another package's doc dir (gcc/cpp/binutils families); that bare entry is also fine.