What does <a:theme> mean in OpenXML?

I'm try to understand OpenXML spreadsheet inner file content. IN some file I found this string . Other tags has same prefix. Also tags may have prefixes p: w开发者_开发知识库: etc.

Can you help me undestend the meaning of these prefixes in tags?

You can search for each tag and the full specification of Open XML at DII or download the PDF from the ISO site to read offline. All of these tags have a specific meaning in the construction of one or more formats for Word/Excel/PowerPoint 2007/2010 documents, spreadsheets and presentations.

The one that you mentioned above, <a:theme> is the parent tag for the construction of different templated looks/feel documents, such as their fonts, font sizes, color schemas, etc. See here for a description.

If you're looking to get a little more familiar with the standard, there is a great eBook that can be downloaded and read: Open XML Markup Explained.