Entries from the "Gold Book" should be reproduced in new Recommendations exactly, unless the conditions of instruction 2 apply. Authors should remember that any new definitions of terms will appear eventually in the "Gold Book", and the compilers of the "Gold Book" should not have to make a decision between existing and new definitions.
There are two minor but universal exceptions:

1. In the "Gold Book", entries have frequently combined a definition with a commentary on this definition. According to the previous sections of these Guidelines, commentaries or further explanations of the definition should be placed in notes, so that the definition and comments on it are clearly separated. This is the recommended procedure, even though there are no plans for a systematic revision of all definitions in the "Gold Book".
2. Starting an entry with a definite or indefinite article is not acceptable, according to the Guidelines.

Example:

asymmetric

Lacking all symmetry elements (other than the trivial one of a one-fold axis of symmetry), i.e. belonging to the symmetry point group C₁. The term has been used loosely (and incorrectly) to describe the absence of a rotation-reflection axis (alternating axis) in a molecule, i.e. as meaning chiral, and this usage persists in the traditional terms asymmetric carbon atom, asymmetric synthesis, asymmetric induction, etc.
In this entry from the "Gold Book", the first sentence is clearly the definition, while the second sentence is a commentary on use of the term. Therefore, the second sentence should be placed in a Note when used in new Recommendations.

Entries should be modified only after careful consideration. Continual modification of entries is counterproductive to maintaining the Gold Book as an authoritative source. Entries may be modified in the following circumstances:

1. The entry contains one or more errors. The author should correct the error(s), and add, at the end of the entry, "Corrected from [x].", where [x] is the reference number for the "Gold Book". Reviewers will be able to question this correction.
2. The author considers that an entry is, for example, not clearly written, superseded by newer developments, not sufficiently complete for the present Recommendations, etc. The author can propose a new definition or new Notes, or both, but must be ready to defend the changes to reviewers. At the end of the entry, the words: "Modified from [x]." should be added, along with any supporting references. References should be at the end of the entry, not within the text.
   Changing an existing "Gold Book" entry implies that the entry becomes longer, through either the definition itself or notes. Longer entries in the form of explanatory notes usually make the entry more useful to the reader. It is difficult to conceive that a shorter entry will be acceptable.