Mathematics Subject Classification (MSC)
Mathematical Subject Classifications (MSC) are categories created to classify mathematics by the mathematical databases MathSciNet and zbMATH. MSC is made up of codes for 63 different major mathematical disciplines, with multiple levels allowing for even more precision. MSC classifications are five characters long. The first two characters are numbers representing an article's major mathematical discipline. The third character is a letter describing the article's sub-discipline. The final characters are numbers representing the specific focus of the article. For example an an article which was assigned 11D07 would be in Number Theory (11) with focus on Diophantine Equations (D), specifically The Frobenius problem (07). All articles and books indexed in MathSciNet are provided MSC values, more than one if needed, by subject area experts when added to the database. MSC is updated every 10 years to stay on top of changes and trends in mathematics. zbMath provides a browseable page of MSC values for free if you want to dig deeper into the classifications.
About MathSciNet
MathSciNet from the American Mathematical Society is the leading mathematics indexing and abstracting database. It provide abstracts from more than 3100 mathematical journals and many thousands of books, conference proceedings, theses, and technical reports indexes. MathSciNet goes beyond simple bibliographic information, it also incorporates the content of the American Mathematical Society's Mathematical Reviews. These article reviews are written by experts in the article's mathematical content and exist for a significant percentage of the papers in the database, including many from as far back as 1940s.
How to Search MathSciNet
Searching MathSciNet is very similar to using advanced searches in library catalogs or databases. It provides users the ability to search publications, authors, journals, or citations. What sets MathSciNet's search apart from many other databases, is its unique identification of authors and articles, and its use of the MSC (mathematical subject classification) system.
Upon visiting MathSciNet you will be presented with a search bar. If you know the name of an author or an article title you can start typing it into the search bar, but if you are doing a wider search you will have to use field codes.
For example if you wanted to know what articles Fan Chung wrote about linear algebra and its connections to graph theory then I would use the query:
au:"Chung Fan" AND pcsc:"05C50"
Where au:"" is the author field, and when I start typing in Fan Chung's name it provides me with a drop down of author names and I chose Chung Fan.
Then I type AND followed by pcsc:"05C50" to search the Mathematics Subject Classification Primary and Secondary for the subject Graphs and linear algebra. This is the results:
Do not worry about having to remember a bunch of field names, clicking on Show All Fields and then clicking on the field you want it will auto-populate in the search bar. You can also click the Show Classic Interface link which brings up a traditional advanced search with drop down menus for field searching.
If you think you will need to do the same search regularly, MathSciNet allows you to Pin any search. Just click on Search History, choose the search you want, and click the Pin button on the right hand side.
MathSciNet has also made major progress in solving a major problem in database searching: telling author's with the same name apart from one another. MathSciNet accomplishes this by assigning unique identification numbers to each author. You can search for a specific author by clicking the Author tab on the MathSciNet home page and then use their name or their ID number (if known).
Clicking on an author's name elsewhere in the database will also bring you to their MathSciNet profile. If you are the author of a mathematics paper indexed in MathSciNet, you will also have an author profile which you can log into and add a photo too or otherwise edit.
The Journals tab provides the ability to search for publications by name or ISSN.
The results link to a journal profiles with information about the publisher, previous journal names, dates of publication, and how it is indexed in MathSciNet. You will also find links to issues and articles, citation data, and RSS feeds you can subscribe to which will alert you when MathSciNet adds new articles from the journal.
Finding Connections in MathSciNet
MathSciNet also offers a set of unique tools you can use to explore the connections between the authors in the database.
The first tool, available through MathSciNet's free tools and is called collaboration distance. Enter the name of any two mathematicians and the database will find the shortest distance, measure by co-authored papers, between them.
You can also explore connections through an author's MathSciNet profile page.
All you have to do is click on co-authors. Then you can sort the list of all of the mathematician's co-authors by name, publication count, citation count, or earliest publication.
In many cases the profile page also provides a link to an author's mathematical genealogy from the Mathematical Genealogy Project. From there you can explore student advisor connections of over 200,000 mathematicians, with information often going back centuries.