(Updated Dec 6, 2021)

Javascript and Cookies
Sidebar
Print Options
Background Colors
Searching
Browser Compatibility

Javascript and Cookies
This site uses javascript to provide a number of enhancements. These include:

• drop-down menus on home and article pages
• expandable site map
• variable sidebar on home and article pages
• print options
• choice of background colors (albeit a limited range)
• highlighting of search results

A number of the above require settings to be preserved throughout a browsing session. On this site this is accomplished by using session cookies. This type of cookie is automatically destroyed when the browser is closed so settings will not be "remembered" if the site is revisited at some subsequent date. We do not set any persistent cookies.

To the best of our knowledge we are exempted from the current EU requirement for users to "opt in" to the use of cookies, due to the benign nature of the cookies we set, and the fact that we are a non-commercial organization with a website that carries no advertising.

For users who do not wish to enable javascript and/or session cookies, all the articles on the site are available through the site map. In the absence of javascript the entire tree is expanded.

Sidebar
The contents of the sidebar can be changed by accessing the drop-down menu at the top of each page and can be subsequently hidden if desired (except on the home page). The variable sidebar is not available if javascript or session cookies have been disabled.

Print Article
The "Print Article" button available on most article pages (but not the Home page or pages in pdf format) enables javascript users to choose whether images in an article should be printed or not. After this choice the browser's print dialog box is called to perform the remainder of the printing procedure. For javascript disabled browsers article contents will print without images – the default option – but the browser will still use our print style sheet, ensuring a suitable format for output to paper.

Background Colors
There are no alternative style sheets for the site but we do offer a limited range of background colors which we consider compatible with the predominant theme (green).

Searching
Searching is applicable to most on-site articles. In the case of pdf documents there are serious restrictions: searching is carried out on the main content only, with appendices and references generally not included; matches are listed by page only; there is no highlighting of the referenced pdf pages; page numbering refers to online pages and may differ slightly from hard-copy numbering; although clicking on a page link will usually open a pdf document at the correct page, subsequent links to other pages within the same document may fail. In addition, it should be noted that we have only prepared ancillary files (to enable the above search procedure) for a limited number of pdf files on the website and that some pdf documents cannot be searched even from within Adobe Acrobat (because of font incompatibilities). Words in pdf files which have been uploaded from external sources for reference purposes only – i.e. not listed in our contents (site map) pages – cannot be searched for using our bespoke search program. However, the majority of articles on the website are not in pdf format.

Four search modes are provided:

1. Context search. This is the default method. A maximum of five search terms are allowed (comprising not more than 128 characters in total, including spaces). Each term must be separated by a space from following terms and can consist of a word or a phrase (phrases must be enclosed in double quotes). A match is recorded when all the search terms are found in the same paragraph. This is particularly useful for this site where many of the paragraphs are quite long and topic focused. There may be several matched paragraphs in a given document and extracts are provided from each. Documents referenced will have the matched paragraphs highlighted if javascript is enabled. Although many "common words" are discarded there is an upper limit to the number of matches permitted to guard against spurious searching for trivial expressions. Also, to avoid abuse, in words only English alphanumeric characters and, optionally, hyphens are permitted; within phrases, periods, commas, colons, apostrophes, and hyphens are allowed in addition to alphanumeric characters. The search algorithm employed seeks to match the singular and plural of input words as well as alternative tenses. For some shorter words this is not possible, but the majority that have relevance on this site will match singular, plural and regular past tense.
2. Name search. This is somewhat of a misnomer – the method can be used to search for any phrase. In summary the input for this mode is: a phrase not more than 128 characters long (not enclosed in double quotes), comprising alphanumeric characters and, optionally, hyphens, commas, periods, colons, apostrophes, and quotes, the latter having no special meaning. When trying to match a name containing "special" characters search for a portion of the name which does not contain such characters. Matches are sought everywhere within the document, with the exception of the document title. The algorithm is simply an exact match of the input phrase. Matches are returned as a date ordered list of documents. Documents accessed from the list will have matched elements highlighted if javascript is enabled. This can have some curious effects. In some cases entire columns of tables may be highlighted.
3. Frequency search. As the name implies this method counts the number of times the search terms are matched in returned documents. The rules regarding allowed input are identical to those for the Context method. A list of matched documents (documents in which each term is matched at least once) is returned, ordered by "total" matches. There are no extracts nor highlighting in the documents themselves. The matching of words is similar to that employed in method 1.
4. Title search.Use this specifically to find a particular document. The rules governing input are exactly the same as for method 1. A match is recorded if any of the search terms occur in a document title. An unordered list of matching documents is returned.

Browser Compatibility
As of writing, the site does not include features that make it impossible to run on older browsers, such as Internet Explorer 7, etc. However, we no longer test the site on these browser versions. For the last ten years we have been testing on (at the time) the latest versions of Chrome, IE/Edge, Firefox and Opera, on the Windows platform, and occasionally Safari. More recently we have included limited testing on Android and Apple tablets. Hopefully some initial problems with these devices have been ironed out. While we endeavour to use cross-browser code which should be recognised by all modern browsers, there will undoubtedly be differences in rendering across platforms and between browsers other than those tested. (At present we do not have special provision for narrow format devices such as mobile phones.)