This section provides, first, a brief explanation of the basic system of analysis adopted in writing the notes on the bilateral articles and of some of the terms used, and, second, a note on the meaning and use of the symbols employed in the diagrams.
The essential aim of the analysis is to show, with all appropriate brevity, how the treaty under consideration differs from the 1977 OECD Model. The broad general principle is that the notes will detail the differences from the Model and not the similarities with it.
Occasionally a bilateral treaty will contain a much shorter article than that in the Model. In such a case the note may indicate that "the article simply provides...." and then quote the article more or less in full.
There are a number of expressions used in the notes which it may be helpful to clarify.
"Residence country" or "residence state" indicate the state of which, or in which, the person affected by the article, is a resident. This is usually the state to which the relevant income flows.
"Source country" and "source state" indicate the state in which the income arises. Similarly "situs state" means the state in which is situated property (usually immovable property) or an establishment or base.
The term "real property" is sometimes used in places where the Model uses "immovable property" but it is clear that the terms are effectively identical: where this occurs, the note may not comment on the difference of terminology.
"Sole taxing rights" is a phrase used when an article provides that income or capital or capital gains are taxable only in one or other of the contracting states.
"Exemption" describes complete relief from tax in a state on a particular form of income (or a tax rate of nil thereon).
"Remittance basis" describes the situation in which a resident of, or in, a state is charged to tax on income from sources outside that state, but only on so much of it as is remitted to or received in the residence state.
"The Model article" describes the 1977 OECD Model text. "The bilateral article" describes the actual article in the treaty being analysed. A "non-standard paragraph" or "non-standard provision" is a paragraph or provision which does not appear in the Model.
"Treaty" is the term used to include "agreement", "convention" or "arrangement" etc. "Protocol" means any later amending or supplementary Protocol or convention. "Protocol of Signature" means any Protocol, Exchange of Notes, or other addendum to the relevant treaty which is appended at the time of signature or between that date and the date of the treaty's entry into force - usually recording understandings about the effect of the treaty in particular respects, but often expanding it with additional provisions.
When we started work we knew that there would be a good many treaties in which individual articles copied the OECD Model, possibly with minor differences due to the need to translate the text into other languages (and relate it to domestic law in the two countries involved). We thought that if we could represent such articles by visual symbols it would save a great deal of time and space. We then realised that to employ some kind of diagram for each country's treaties would convey information about that country's treaty system, and about its use, amendment or rejection of the Model generally much more rapidly, if more briefly and roughly, than a simple narrative.
Thus the reader will find three kinds of diagram in this work. The first, in the notes on each article of the Model, is a diagram showing each country's position vis a vis the others on the particular article and how this position compares with the Model. The second diagram, in the introduction to each country chapter, shows how closely or otherwise that country adheres to the Model in all the articles in its own treaties. This summary diagram is made up of lines which are taken from the third type of diagram, shown at the head of each country's note on the individual article in its treaties, which indicates the way in which each Model article has been used, not used, or adapted in that particular country's treaties.
There are six symbols in all:
This indicates an article
which is identical to, or substantially the same as the OECD 1977
Model (we have chosen the 1977 Model because very few treaties
have so far used the 1992 or later texts). Many treaties have of
course used the 1963 Model, and we have had to take a view,
article by article, as to whether the 1977 Model itself is
"substantially the same" as the 1963 text. Where we think that
it is we have used .
indicates that, while using the
wording of the 1977 Model, or the
1963 Model if that is substantially the same, a treaty adds a
specific provision (whether in the article in point or elsewhere)
which, even if it qualifies the general rule, does not detract
from its generality, or there is, in the article or elsewhere,
a separate or related provision, or there is a note about the
article, for example referring to explanatory material in a
protocol of signature or details of an earlier treaty.
This indicates that the
general rule of the 1977 Model applies with differences set out
in the notes below - differences which range from important
omissions to minor additional provisions and explanatory or
clarificatory additions. We have tended to err on the side of
caution and, in many cases, minor differences, particularly where
there are more than one, have been commented on, and consequently
signalised with a , even though they
could strictly have been ignored as not in conflict with the
general rule, and the symbol employed.
The fact therefore that the symbol is
used should not be taken as necessarily indicating a very wide
deviation from the Model. Where differences which by themselves
would merit are combined with
differences for which the appropriate symbol would be we use
(effectively pointing to a note which may cover several factors).
Moreover, there may of course be early treaties where the same
rule as the Model's appears in a different form, possibly because
its negotiators were using an evolving principle, which was later
accepted, or they had access to drafts of articles which were
being considered by the League of Nations or the OECD. It would
thus be the form of the article rather than its substance which
would explain the use of the . For this
reason too, the importance of the differences indicated by the
symbol (or even in some cases the 
symbol - on which see below) should not be
exaggerated.
without a corresponding entry draws
attention to a general note at the head of the notes on the
article which covers that country's position.
indicates that what we feel is the
general rule in the Model has either not been observed or has
been breached in some important manner. Again, the notes describe
the differences from the Model.
means that the particular OECD
article is not represented in any form in the treaty. 
may also be used where there is no
equivalent provision but a note draws attention to matter in the
treaty or in a protocol, or in an earlier treaty, or even in
domestic legislation, which may be relevant.
indicates that there is no current
treaty between the two countries concerned.
Numbering of articles
The second line in the diagram at the head of each country's note on an article of the Model gives the number of the article representing the Model in the particular treaty. With regret we have been forced to give up the Roman numerals appearing in some treaties. XXIIIA has its drawbacks: we use 23A instead. Some countries will have more than one article which ought to be mentioned, if, for example, the OECD provisions have been divided up. To save space however, we list only the main two.
Where treaties are superseded or amended
The symbols refer to the articles in the latest treaty between the relevant countries, or to the articles as amended by the latest amending protocol to the treaty, even if, at the time of going to print, it was not known if the latest treaty or protocol was yet in force. Where articles in a treaty are superseded or amended by a recent new treaty or amending protocol the notes on the articles will generally describe both the old and the new articles. This will not usually be the case however where the date when the change became effective is earlier than 1-1-1994. The old and the new articles will normally be distinguished by inserting the year of signature of the relevant treaty or protocol at the head of the first paragraph of the notes in point. Thus references to a 1995 treaty will be to a treaty signed in 1995, and not necessarily to one coming into force in or effective from a date in 1995.
Points affecting individual articles
What we take as the general rule in force for each article in applying these symbols is, where necessary, set out with the notes on each of the articles of the OECD Model, together with, in some cases, more detailed explanation.