CTAN update: siunitx

CTAN Announcements ctan-ann at ctan.org
Tue May 18 15:17:43 CEST 2021

Joseph Wright submitted an update to the



Version:  3.0.0 2021-05-17
License:  lppl1.3c

Summary description:  A comprehensive (SI) units package

Announcement text:
 Version 3 is a major update to `siunitx`, which has largely been
 re-written internally. A significant number of key-value
 settings have new, more descriptive, names. Where possible,
 older names are mapped to newer ones internally: you will be
 warned in the log if this is the case.

 It is possible to use the LaTeX kernel mechanism to load the
 last version 2 release for documents that cannot be successfully
 processed using version 3. This can be achieved using

 In version 3, the document commands have been revised to be more
 descriptive. As such, the commands `\SI`,`\SIlist`, `\SIrange`
 and `\si` remain available but are not recommended for use in
 new use.

 Some changes have been made to the semantics of commands or
 options. Most notably
 - prefixes cannot now be given without units;
 - prefixes can only be interconverted with numbers as part of a
   quantity, not as stand-alone units.

 The font control system has been completely re-written for
 version 3. The method used in entirely different from version 2.
 Emulation is therefore not provided for some aspects: if you
 need non-standard font settings, you will need to adjust your

 The input approach for version 3 is slightly more structured and
 restricted than for version 2. As well as the updated names for
 document commands, this means that
 - Products of numbers must now be given using the dedicated
   `\numproduct` and `\qtyproduct` commands;
 - Quotients of numbers are only supported as literals;
 - Complex values need to be given using the dedicated command

 The letter used for a numerical tabular column can now be
 selected by the user: the letter `S` has been retained as the
 standard interface. The unit column (`s`) has been removed from
 this release. It can be emulated using the `collcell` package,
 for example

 A new approach has been taken to providing non-Latin symbols for
 use in units: these are now handled directly where needed, for
 example in the definition of the `\micro` prefix.

 If you are using `table-column-width` to have fixed-width
 columns, you also now need `table-fixed-width` to set this
 option active.


The package’s Catalogue entry can be viewed at

The package’s files themselves can be inspected at


   Thanks for the upload.

     For the CTAN Team
    Petra Rübe-Pugliese


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