Encyclopedia of Chess Openings.

I could not find an online sample of ECO, but the sixth page of this link shows something that is somewhat similar to the way things look in ECO:
http://www.qualitychess.co.uk/ebooks/BTOG-Update.pdf
That is actually a supplement to Beating the open games by Mihail Marin.
https://web.archive.org/web/20140626195205/http://www.chesscafe.com/text/hansen102.pdf
At times (page 6, for example), Marin used an ECO sort of style in order to present information. If a buyer has never seen that sort of thing before, some disappointment might be experienced by one who wanted more use of ordinary language.

i just remembered, i scanned A56 from volume A for a mate, it's on my google drive account...

@Jengaias -

Don't try to tell me what I understand.  Spare me your arrogance.  You have consistently exhibited in these forums your compulsion for contentiousness and argumentation.  You were even banned from a club on chess.com which we both belonged to because of your personal attacks of other members of the club whose views you (typically) disagreed with.  My recommendation to all who have the misfortune of dealing with you is to ignore you - which I will do henceforth.

My impression is that Nunn's Chess Openings was indeed popular when it was published, but that was back in 1999. However, if one is considering books from the 1970s and 1980s, then perhaps the age of NCO is not an issue.

MCO15 was about 9 years ago, but, even then, there was some grumbling about it:

"... [Modern Chess Openings (15th ed.)] pretends to be everything for everybody, but it isn’t; it pretends to be up-to-date and relevant in all chapters, but it isn’t; it should be a good book, but it isn’t. ..." - FM Carsten Hansen (2008)
https://web.archive.org/web/20140626165820/http://www.chesscafe.com/text/hansen110.pdf

A little later, there was the Small Encyclopaedia of Chess Openings.
https://web.archive.org/web/20140627063241/http://www.chesscafe.com/text/hansen145.pdf

Judging from the absence of updates since then, chess players seem to have subsequently turned to computer products.

Carsten Hansen has just published his own set of openings books...

Can you give us an example of a title?

Ouch...!  Well, now we know where Carsten Hansen stands.

Of course, no openings "reference" book purports or attempts to be comprehensive with respect to every playable line or the latest developments in opening theory.  But books like MCO, FCO and NCO can serve a purpose (even if dated), especially for those looking for a single book which can serve to provide an introduction, overview or survey of the main lines and variations of all the major openings.  

Before the existence of the extensive computer databases which are so prevalent today, these books were the primary means by which players could (within a single book) gain exposure to all of the major openings.  From that perspective they were very useful.  They can still serve that purpose today, particularly for the less accomplished player, as long as the limitations of the books are understood.  

It appears that gambit-man may be referring to Carsten Hansen's recent book series...

"Catastrophes & Tactics in the Chess Opening..."

https://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Dstripbooks&field-keywords=carsten+hansen+catastrophes&rh=n%3A283155%2Ck%3Acarsten+hansen+catastrophes

ECO, NCO, MCO and Batsford Chess Openings all have tables with lines/variations in algebraic notation, footnotes, and an evaluation symbol (Numeric Annotation Glyph) at the end of each line.

Van der Sterren's Fundamental Chess Openings, Watson's Mastering the Chess Openings 1-4 and Stefan Djuric's Chess Opening Essentials 1-4 have English sentences which describe the openings in general terms.

"... what I have found is that many games, even amongst the strongest players, contain errors and mistakes, some quite significant ones, as soon as the players depart the theory that is known to them.

This book, the first in a series of five, aim to take a look at some of those games, but only the ones that are of 15 moves or shorter. Of course, for a game to end within 15 moves, one of the players has to have made one or more serious mistakes. ..."

It doesn't sound like a series in the same category as ECO, etc. Anyway, thanks for the help.

Today, from the point of view of exposing the less accomplished player to all of the major openings, I am inclined to think that one is better off with books like Fundamental Chess Openings,

https://web.archive.org/web/20140626173432/http://www.chesscafe.com/text/hansen128.pdf

Understanding the Chess Openings,

https://web.archive.org/web/20140627031504/http://www.chesscafe.com/text/hansen76.pdf

Back to Basics: Openings ,

http://www.thechessmind.net/blog/2010/1/30/a-brief-review-of-carsten-hansens-back-to-basics-openings.html

Winning Chess Openings,

https://web.archive.org/web/20140627132508/http://www.chesscafe.com/text/hansen173.pdf

and The Mammoth Book of the World’s Greatest Chess Games.

https://web.archive.org/web/20140708233403/http://www.chesscafe.com/text/review782.pdf

"...[The encyclopedic] type of presentation [of opening theory] uses tables of variations, with individual numbered variations, and alternatives given in footnotes. For new players, I cannot recommend books that use type of presentation, because the explanatory prose that elaborates typical plans and ideas is usually absent, thus leaving the student without any clear idea why certain moves are played or even preferred over other apparently equivalent moves. ..." - FM Carsten Hansen (2010)

Spongey -

gambit-man's comment appeared to refer to Hansen's "just published... set" of openings books.  If you check Amazon for his books you can see that the ones I cited fit that description....

Not sure what description you are referring to. This is part of a description that I found:

"... what I have found is that many games, even amongst the strongest players, contain errors and mistakes, some quite significant ones, as soon as the players depart the theory that is known to them.

This book, the first in a series of five, aim to take a look at some of those games, but only the ones that are of 15 moves or shorter. Of course, for a game to end within 15 moves, one of the players has to have made one or more serious mistakes. ..."

That sounds to me like a series that differs in important ways from ECO, etc. Anyway, again, thanks for the help.

I'm referring to the following comment by gambit-man....

gambit-man wrote:

Carsten Hansen has just published his own set of openings books...

I make no claim that the books he refers to are similar to ECO, FCO, MCO etc...

I thought it was worthwhile for me to add that Catastrophes & Tactics in the Chess Opening does seem to me to differ from ECO in important ways.

"... what I have found is that many games, even amongst the strongest players, contain errors and mistakes, some quite significant ones, as soon as the players depart the theory that is known to them.

This book, the first in a series of five, aim to take a look at some of those games, but only the ones that are of 15 moves or shorter. Of course, for a game to end within 15 moves, one of the players has to have made one or more serious mistakes. ..." - Carsten Hansen

OK Spongey....I misunderstood you....thanks for the clarification!

would you like me to google it for you?

About five hours ago, RussBell came up with the title, Catastrophes & Tactics in the Chess Opening. If that is what you were writing about, I do not see a need for any more from you.