A brief history of the Code

    The history of the Code that governs the scientific names of algae, fungi,
and plants (traditionally named the botanical Code) may be taken to have
started in 1867, although nomenclature itself obviously is considerably older. 
Indeed it is characteristic of the Code that it is a set of retroactive rules,
governing names that (mostly) were published before the Code that governs
them.  In many ways the Code is a codification of nomenclatural practice rather
than an independently growing set of rules.  This aspect of retroactiveness
makes the subject of nomenclature such a delicate one:  a change in a rule may
instantly wipe out a long-existing name or may resurrect a name that has not
existed for a long time.

    For convenience’s sake the editions of the Code since 1867 may be divided
into three groups, published in three time periods:
    1)  the ‘initially French’ period, 1906-1935, with John Briquet as the central
figure (succeeded by T.A. Sprague).  In this period, proposals to amend the
Rules were supposed to be  “in Latin, English, French, German, or Italian”
(submitted in one hundred copies).  The Synopsis (Recueil synoptique) and
the Proceedings were entirely in French, up to, and including, the 1930,
Cambridge Congress.  The three editions of the Rules were each published in
three languages, but for the 1906 and 1912 Règles internationales de la
Nomenclature botanique
the French version had pride of place.  In the third
edition (1935), edited by A.B. Rendle, the English version had become the
primary one, as the International rules of botanical nomenclature, although
the preface was in German.  In this period, the Rules / Règles were published
by Gustav Fischer Verlag, in Jena, and were orange-coloured paperbacks (or
were included in orange-coloured paperbacks). By content, this is the period
of getting things together (getting international agreement and settling the
basic structure of the system of names: priority, the type-method, effective
publication, valid publication, legitimacy).
    2)  the ‘Dutch’ or ‘Utrecht’ period, ca. 1950-1983, with Joseph Lanjouw and
Frans Stafleu as central figures.  In this period the Code, as the International
Code of Botanical Nomenclature
, continued to be published in three languages
(mostly:  the 1952, Stockholm Code lacked a German version, while the 1956,
Paris Code also included a Spanish version), but with the English version
having pride of place.  In this period, the Code was published in Utrecht, and
always is a separately printed book, cloth (an occasional reprint in buckram),
typically dark blue (the 1956, Paris Code was more reddish, being purple), up
until the 1978, Leningrad Code, which is the first of the multi-coloured Codes.
By content, this is the period of getting properly organized (starting the IAPT,
Taxon, Regnum Vegetabile, the ING, TL-2).
    3)  the English-only period, ca. 1988 onwards, with as central figures Werner
Greuter and John McNeill (later joined by Nicholas Turland).  In this period,
the Code is published in a single language, English.  The layout of the Code had
started to change with the 1978, Leningrad Code and continued to evolve.  The
2012, Melbourne Code may represent the start of a new period, as it has a new
title (the International Code of Nomenclature for algae, fungi, and plants), is
new in that is published in two separate volumes and has a changed layout that
in some respects is new, but in others represents a return to the Rules.  In this
period, publication of the Code is in the hands of Sven Koeltz, and always is a
separately printed book (two books in the case of the Melbourne Code), a
hardcover (shifting from cloth to a glossy hardback with the 2006, Vienna Code),
every time in a different colour. By content, this is a period of renewed change
and growth.

    These periods are not marked by sharp breaks in all respects:  the ‘Dutch’ or
‘Utrecht’ period may be taken to have started with the 1948 Utrecht conference,
or even with the 1935, Amsterdam Congress. The 1950, Amsterdam Supplement
is odd in several respects being only a supplement (not a full set of Rules or a
full Code) and published only in English;  it was compiled by Sprague, and
included in a volume edited by Lanjouw, which was printed in the U.S.A. 
However, the ‘Dutch’ or ‘Utrecht’ period certainly started no later than with the
1950, Stockholm Congress, when the IAPT was founded. 
    The linguistic issue is not all that clearcut either. The Recueil synoptique and
the Proceedings were entirely in French, up to, and including, the Cambridge
Congress (but the resultant Rules used English as the prime language).  They
were entirely in English for the Amsterdam and Stockholm Congresses.  For
the Paris Congress, the Recueil synoptique was in both French and English
(side by side) while the Proceedings were in three languages (each speaking in
his own language, except the Spanish which was translated; proposals in
Spanish had been allowed, accompanied by an English, or French, translation). 
Proposals in a language other than English were allowed up to, and including,
the 1981, Sydney Congress. 
    The second transition is also gradual in the sense that the involvement of
Stafleu decreased gradually, and that the change in typography also is gradual. 
Greuter left the Editorial Committee after the St Louis Code, to return for the
Melbourne Code.

An outline of changes in the Code

    The following highlights only the most notable changes in the Code;  a much
more detailed account of changes may be found in the Prefaces of the respective

    The 1867 Lois, aka the Candollean Laws, or the Paris Rules, adopted by the
1867, Paris Congress, started to put botanical nomenclature on a formal footing
and were the focus of intense debate (with several competing sets of rules being
proposed).  This debate resulted in the appointment of a Rapporteur général
(then unhyphened) at the 1900, Paris Congress (I IBC) with the task to organize
the debate.  In the meantime there had been an (unofficial) 1883 update.

    The 1905, Vienna Congress (II IBC) saw the start of an international Code
(the 1906, Vienna Rules), even if at the time it was not universally followed. 
It saw a formal decision on the starting point of botanical nomenclature, namely
the Species Plantarum of 1753 (and not the Genera Plantarum of 1737), and on
the so-named “Kew Rule”, which was not included.  What was included was the
principle of conservation of names (protecting selected names against the normal
working of the rules) although only for names at the rank of genus.

    The 1910, Brussels Congress (resulting in the 1912, Brussels Rules, aka the
International Rules, ed. 2) was relatively quiet.  Those who felt left out by the
“chiefly of Vascular Plants” in the title of the 1906 Rules asked for attention for
their respective groups.  The new Rules saw the introduction of specified starting
points, for each of the different groups, and started to take notice of special needs
for groups such as fossils and fungi, including the introduction of what would,
half a century later, become Art. 59.

    The 1930, Cambridge Congress (resulting in the 1935, Cambridge Rules,
aka the International Rules, ed. 3) was again very notable, a place for major
reconciliation:  the clash with the adherents of the American Code was resolved. 
This had been preceded by a decade of work, especially by Sprague (aiming at a
unified “World-Code”) and Hitchcock (presenting the “Type-basis Code”), laid
down in a single set of proposals (actually a proposed complete replacement,
which over the history of the Code happened some half a dozen times, with the
Philadelphia / American Code probably the most famous; most such proposed
replacements were notably unsuccessful).  Very many of these proposals were
accepted at Cambridge, while others found their way into the Code later.
Important concepts like the type-method, effective publication, valid publication,
legitimacy and illegitimacy were accepted here.  The option of conserving names
was extended to include names of families.  The general principle of a caretaker
International Executive Committee (later renamed as the General Committee)
was adopted here, to take care of general coordination and to carry on in case of
war.  The Cambridge Rules also saw the introduction of the term “tautonym”
(dealing with a point of difference with the American Code).

    The 1935, Amsterdam Congress again was relatively quiet, mostly
confirming the changes made at Cambridge, and tidying up matters left over
from the Cambridge Congress such as the rule on provisional names. It also
saw the adoption of what has now grown into Rec. 50A to 50F, and it was here
that a list of conserved family names was first adopted by the Congress,
although it was discontinued in the 1956, Paris Code (the 1959 Congress
adopted a new list). This is the only Congress not resulting in a full Code, but
only in the unofficial 1947, Brittonia Rules and the official but minimalistic
1950, Amsterdam Supplement, the latter of which is represented here by the
‘Amsterdam Rules’ (synthesis).

    The 1950, Stockholm Congress (resulting in the 1952, Stockholm Code,
the first to use “Code” in the title), was, again, one of the big turning points,
with the founding of a supporting organisation, the IAPT, with its own journal
Taxon, and its own book series, Regnum Vegetabile, which would take care of
publishing all proposals to amend the Code and proposals to protect names (at
this stage these were still proposals to amend the Code).
         The process of amending the Code was also altered here: up until this
time only matters not dealt with by previous Congresses could be proposed,
but Lanjouw opened this up.  He also instituted the preliminary mail vote.
         The 1952, Stockholm Code was published in blue cloth (that is, as a
hardback), as opposed to the Rules which had been published as softbacks, in
orange wrappers.  The layout and typography were also changed dramatically,
changes which did not all stay, but it was here that Recommendations got the
same number (plus a letter) as the Article they were following.  Also, the 1952,
Stockholm Code has the most Articles of any edition of the Code, and the most
dealing with separate topics;  the content of these Appendices
would later be integrated into the body of the Code, with the last survivor (the
Appendix on names of hybrid taxa) integrated into the body of the 2018 Code
         An important change in the rules was the adoption of the autonym
concept (although at that stage the term “autonym” was not used;  the term
itself was introduced with the 1972, Seattle Code).  It was here also, that
taxon” became the accepted term for “taxonomic group”.  The option of
conserving names was extended to all names from the rank of order to
genus (although in practice this was never followed up by the actual
conservation of any name in the newly added ranks). 

    The 1954, Paris Congress (resulting in the 1956, Paris Code) is mostly
noted for completing the changes started in Stockholm.  The Synopsis of
Proposals was given the format surviving to this day.  The same applies to
the basic format of the Code, with its three “Divisions” and the new
Preamble” and “Principles”, these last were created by the conversion of
Art. 1 to 11.  It was at this point that two important principles were lost: 
“The essential points in nomenclature are:  [...] to aim at fixity of names”
and  “The rules of nomenclature should be simple and founded on
considerations sufficiently clear and forcible for everyone to comprehend
and be disposed to accept”.  The Div.  III on the governance of the Code
was completely new, although building somewhat on what had been accepted
at Cambridge, but had been dropped in the Stockholm Code.  It also saw the
introduction of what is now Art. 60.8.

    The 1959, Montreal Congress (resulting in the 1961, Montreal Code)
eliminated the Appendix on fossils (introduced with the 1952, Stockholm
) and integrated its provisions into the body of the Code.  It was decided
to have priority not apply to names above the rank of family; the option of
conserving names was adjusted accordingly, to be restricted to names at the
ranks of family down to genus.  A new list of conserved family names was
adopted (the previous one, of the 1935 Congress, had been dropped from the
Paris Code).

    The most notable changes at the 1964, Edinburgh Congress (resulting in
the 1966, Edinburgh Code) were a revision of Art. 59 and of the provisions
on hybrid taxa.  An attempt to get extraterrestrial plants included in the Code
was dealt with summarily.

    The 1969, Seattle Congress saw the introduction of the term autonym, while
at the same time limiting the autonym principle to taxa that include the type of
a family, genus or species (that is, it no longer applied to taxa that include the
type of the next-higher taxon).  The 1972, Seattle Code is the final edition in a
series, 1952 to 1972, of very similar-looking books: cloth, at the same size, all
blue (except the 1956, Paris Code, which is purplish);  succeeding the 1906 to
1935 Rules, which also shared a very similar look: orange paperbacks, at a
larger size.

    From the perspective of looks and typography, the 1978, Leningrad Code
represents a big change:  it introduced the latter-day tradition of a differently
coloured cover with every edition and introduced numbering of all paragraphs,
instead of just the Articles (and Recommendations).  At the same time, many
Notes were formally upgraded to Rules (which they had been already, in all
but form);  of course, some Notes remained just that: from this point onwards
a Note is something that only explains something that is ruled elsewhere.  A
change of substance by the 1975, Leningrad Congress is that here the option
was created, although execution remained on an ad interim basis, of formally
proposing a name for rejection, these rejected names to be placed on a List
Another change of substance was the adoption of rules standardizing the
orthography of ‘personal’ epithets (it was here that Magnolia ×soulangiana
became Magnolia ×soulangeana), also causing traditional epithets like berteri,
lourieri, etc to be changed to berteroi and lourieroi, etc.  The Leningrad Code
dropped the “Guide to citation of botanical nomenclature” (introduced with the
1952, Stockholm Code).

    From a typographic viewpoint the 1983, Sydney Code continued the policy
of numbering that had been adopted in the preceding edition, and in addition
also numbered all the Examples (per Article);  presumably this may be taken
as the starting point for the latter-day proliferation of Examples.  However,
the 1981, Sydney Congres also made many substantial changes:  it eliminated
the option of conserving names between the ranks of family and genus but
created the possibility to conserve names of species, although only for species
of major economic importance;  protecting names of species had been a point
of contention for a long time (for instance, it had been a hot issue at the 1930
and 1935 Congresses).  The Sydney Congress accepted the concept of
“sanctioning” for names of fungi, and saw a revision of, again, Art. 59, and of
the provisions on hybrid taxa.  It also introduced provisions on orthographical
variants, as well as many smaller changes (for example “botanists” became
“authors”);  this was the Congress where Dysoxylum fraseranum became
Dysoxylum fraserianum.

    From a typographic viewpoint, the 1988, Berlin Code is perhaps the most
indifferent Code ever produced.  It started the recent tradition of publishing the
Code in the year subsequent to that in which the Congress was held. It is a
notably slim volume, being produced in a single language only, English.  By
content, notable changes were the upgrading of the Recommendation on
gender to an Article and the removal of the  “Guide for the determination of
types”  (introduced with the 1952, Stockholm Code), integrating its contents
into the body of the Code.

    The 1994, Tokyo Code shows a major upheaval.  What had been Art. 51 to
72 were shaken up, maintaining only Art. 59 under its traditional number.  Of
these, Art. 51 to 61 were mostly eliminated, with much of the material
absorbed by Art. 7 to 11, while Art. 62 to 69 and 72 were mostly resettled as
the new Art. 51 to 58.  This left the body of the Code with 62 Articles only, the
lowest number since 1912.  A major change by the 1993, Tokyo Congress was
the adoption of the principle of registration, but contingent upon acceptance by
the next Congress.  Another important change was the removal of the restriction
in the conservation of names of species (no longer only for species of major
economic importance) and the adoption of a separate Article on sanctioned
names (names of fungi that enjoy a special status).  The option of formally
proposing a name for rejection was modified;  from this point onwards a name
could be rejected for any reason.  Also, it became possible to suppress a work
(a publication), also an issue long debated:  names in such a suppressed work
(in specified ranks) are not validly published (that is, they don’t exist, as
botanical names).  It was at this point that ligatures such as “æ” stopped being
an allowed component of botanical names.  Typographical changes were the
adoption of consistent italics for all botanical names (at all ranks), rather than
just some of the time, as well as for the word “Code”.  Also, three different
font-sizes were used, for Articles, Recommendations (& Notes) and Examples,
respectively.  There was also a change in the author citation of botanical names,
including the adoption of the standard set out in the book by Brummitt and

    The 1999, St Louis Congress is best known as the Congress that firmly
removed the concept of registration from the Code. It also removed the
requirement for an author citation. The 2000, Saint Louis Code is also the first
that was explicitly written in British English, rather than just using British
spelling (in case of discrepancy).

    The biggest change at the 2005, Vienna Congress (resulting in the 2006,
Vienna Code), was the introduction of the option of formally submitting
names for evaluation of the adequacy of the description or diagnosis for the
purposes of valid publication (the “nomina subnuda” issue).  Another issue
that was settled here is that of the thesis, other than as part of a series:  a thesis
is accepted as effectively published if there is evidence that it was intended to
be effectively published (an ISBN number is such evidence);  this change is
retroactive, and has the potential for surprising effects.  Other noticeable
changes were the new glossary and a shiny cover (first ever) instead of cloth
(the opportunity to produce this in orange, in honour of the 1906, Vienna
, was sadly missed).

    The 2011, Melbourne Congress was one of major change.  The title of the
Code was changed, again.  Electronic publication was allowed (in an online
publication that has an ISSN/ISBN number and that uses the pdf format), as
well as a choice of either English or Latin for the description or diagnosis for
new taxa in all groups (neither change being retroactive).  The special
provisions for fungi and fossils were simplified (and “fossil plants” and
“subfossil” eliminated as terms).  On the other hand an extra requirement was
adopted for publication of names of fungi, involving deposition of key data at
a central depository.  A degree of protection for names between the ranks of
family and genus was accepted.  A large-scale replacement of technical terms
relating to nomenclatural concepts took place.  The 2012, Melbourne Code,
again, is a slim volume (although bulked up by the use of thicker paper), as
most of the Appendixes were published separately.  Typographically, it also
is innovative, with more white space than is traditional.

    The most obvious change made at the 2017, Shenzhen Congress was the
adoption of an almost entirely new and very extensive Div. III.  Another
change is a re-arrangement yielding a separate Chapter F on fungi (to be
governed by mycologists only) and a Chapter H on hybrids. The latter was
App. I; its renaming eliminated the last of the special, non-list, appendices
that were added to the Stockholm Code. Also, the last of the back-door rules
was eliminated through a rearrangement of Art. 60.  A significant change in
principle sees registration gaining a firm foothold.  There is also a noticeable
step away from “harmonization” (with other Codes), not only in separating the
fungal provisions, but also in an expansion of the concept of “replacement
name”, a new definition of “nomenclatural act”, and in the many bibliographic
references that were added in Examples. The long-time policy of only adding a
reference when that reference has content relevant to the point of the Example
was abandoned, and years in author citations (cited to indicate priority) were
expanded to full references in many cases.  These references add solidity and
legal heft, but risk decreased readability.  The lay-out of the 2018, Shenzhen
Code (again published without appendices) is very similar to that of the 2012,
Melbourne Code, but because thin paper was used, the resulting volume is
even slimmer, in spite of having more pages.  It has a semi-gloss cover, for the
first time ever, with, also for the first time ever, a picture on it.

    The hot issue before the 2018, San Juan Congress (with a mandate for
Chapter F only) was DNA sequences as types of names, but this was deferred
to the future.  The most noteworthy action taken was on the recommended
citation of sanctioned names (the colon being eliminated from recommended
author citations).

Paul van Rijckevorsel
Utrecht, 2014

2014 ©, Paul van Rijckevorsel   (all rights reserved)
most recent update:  February 2020