Attributes in Archicad describe and organise all Elements in your model. Attributes in Archicad are e.g. Line Types, Fills, Layers and Layer Combinations, etc.

It is very important to manage Attributes properly, especially when working with multiple files on one project. Attributes are file based, and managed from within an Archicad file. Linked files with differing Attributes will infect each other, making it very hard to control how the project is drawn and ultimately how your drawings will look. Therefore they need to be managed very carefully. 

If not already part of your template, set as many additional Attributes up at the start of a project in one file, and subsequently use that same file to generate other files needed for your project.

Important to distinguish is the difference between the Attribute Manager, which facilitates the organisational management (import / export / naming) of all attributes versus the Element Attributes themselves, which let you edit the actual individual Attribute (e.g. line types, fill types, etc).