If you tried to localize fields, content types or web part titles for Sharepoint Online you already know that it is not trivial process. The main problem is that we can’t deploy farm solutions to Sharepoint Online which may install files on file system. As result we can’t put custom resx files to 15/Resources folder and use them in declaration of our artifacts with special syntax “$Resources:filename,key”.
However it is still possible to localize some frequently used strings like Documents, Meetings, Events, Calendar and others with minimal efforts. Just search for the needed string across OTB Sharepoint resx files which are installed to 15/Resources folder with basic Sharepoint or language pack installation. If you will find such string you still will be able to use it in your artifacts in regular way. For example, localized Documents string may look like this “$Resources:cmscore,ListNameDocuments” because cmscore.resx and its language-specific versions contains translations of Documents string.
Of course with this approach you are limited with strings which present in OTB Sharepoint resource files, but it is better than nothing. In order to be able to use custom resource files for localizing fields and content types in Sharepoint Online much more complicated technique should be used. I will write about one of these technique in one of the future posts.