450 ENGINEERING GEOLOGY/Codes of Practice is qualitatively, rather than quantitatively, defined, so even other geologists can be left uncertain as to the exact meaning intended Over the years, a language of better-defined terms has developed, which should better enable geologists to communicate, not least because there is now a core of standard terminology with which the listeners will be familiar It is the derivation and definition of this standard terminology that is one of the main reasons for recent advances in the drafting and implementation of codes in engineering geology The intention of the ISO and CEN in preparing international standards is to help raise levels of quality, safety, reliability, efficiency, compatibility, and interchangeability, and to provide these benefits economically Standards contribute to making the development, manufacturing, and supply of products and services more efficient, safer, and cleaner They make trade between countries easier and fairer ISO and CEN standards also safeguard consumers, and users in general, of products and services and make their lives simpler The History of Codification in Description Prior to 1970, there was no international standard terminology to allow the communication of descriptions of geological materials or their properties, although some of the larger contracting companies had developed internal guides The first British Code of Practice (CP 2001) was published in the UK in 1957 This code laid down key underlying precepts for the description of soils, in particular that soils should be described in terms of their likely engineering behaviour This basic need is often lost in today’s welter of published guidance However, CP 2001 did not cover the description of rocks Geological sciences continued to develop an increasingly variable use of terminology, but the increasing size of the ground engineering industry made the terminology increasingly irrelevant and no longer tenable The need for a defined and wide-ranging terminology had arrived The use of undefined and narrow terminologies caused confusion and ambiguity in communication and, as a result, frequent contractual arguments arose, often leading to claims based on ‘unforeseen ground conditions’ This was hardly surprising as, if the terminology is variable and undefined, there will always be someone who could misread the ground conditions being predicted For instance, terms such as ‘highly fissured’ and ‘moderately jointed’ were not defined and therefore meant different things to different readers This was addressed when the Engineering Group of the Geological Society of London published, in the early 1970s, a series of Working Party Reports for guidance, for example on core logging (in 1970) and the preparation of maps and plans (in 1972) These reports formed the basis of UK practice and, as it turned out, international practice in many respects Similar activities on the international scene resulted, by 1981, in publications from the International Association of Engineering Geologists and the International Society of Rock Mechanics on field investigation, geological mapping, and soil and rock description In the UK, this decade of guidance culminated with BS 5930 (published in 1981), the seminal National Standard for engineering geological activities It is important to note, however, that even at this stage BS 5930 was designated as a code of practice, meaning that the guidance was advisory rather than normative (i.e mandatory) This designation was maintained in the updated version of BS 5930, published in 1999 The reasons for this relate to the preference of many geologists to not be given edicts on geological terminology However, the designation of codes as advisory has little practical relevance The codes are referenced in contract specification documents and thus become binding In legal arguments about claims or failures, the courts will expect the national guidance to have been followed Therefore, at least by default, the codes of practice have become de facto Standards The publication of international guidance has continued, albeit at a slower pace, with individual nations publishing national guidance documents The designation of such guidance as mandatory or advisory varies, and it is this variance that is now being resolved in the name of international normalization Particular Problem Areas in Combining National Codes Despite the codifications in various countries proceeding independently, there are many cases where the practices of one country have been adopted by another For this reason, the preparation of international codes by the ISO has not been as difficult as might have been anticipated, at least as far as the description of soils and rocks is concerned There have nevertheless been a few difficulties, as outlined below However, the historical development of local codes has tended to reflect and emphasize local