[masraum]

THE knot book is the Ashley Book of Knots.
https://en.wikipedia.org/wiki/The_Ashley_Book_of_Knots

he Ashley Book of Knots is an encyclopedia of knots written and illustrated by the American sailor and artist Clifford W. Ashley. First published in 1944, it was the culmination of over 11 years of work. The book contains 3,857 numbered entries and approximately 7,000 illustrations.[1] The entries include knot instructions, uses, and some histories, categorized by type or function. It remains one of the most important and comprehensive books on knots.
Use as a reference

Due to its scope and wide availability, The Ashley Book of Knots has become a significant reference work in the field of knotting. The numbers Ashley assigned to each knot can be used to unambiguously identify them. This helps to identify knots despite local colloquialisms or identification changes. Citations to Ashley numbers are usually in the form: "The Constrictor Knot (ABoK #1249)", "ABoK #1249", or even simply "#1249" if the context of the reference is clear or already established.[2]

Some knots have more than one Ashley number due to having multiple uses or forms. For example, the main entry for #1249 is in the chapter on binding knots but it is also listed as #176 in a chapter on occupational knot usage.

The Ashley Book of Knots was compiled and first published before the introduction of synthetic fiber ropes, during a time when natural fiber cordage – typically twisted, laid, or braided rope – was most commonly used. The commentary on some knots may fail to address their behavior when tied with modern synthetic fiber or kernmantle style ropes.

And it's available online and downloadable in several formats (including PDF and ePub) from the Internet Archive
https://archive.org/details/TheAshleyBookOfKnots
PDF link - https://dn790008.ca.archive.org/0/items/TheAshleyBookOfKnots/the%20ashley%20book%20of%20knots.pdf