Hi Elizabeth

Thanks for posting in the community. If you've applied a Master Page to another page tab in your document you should be able to edit/add content to the page tab. But you will be unable to alter any components of the applied Master Page while in that page tab. You can convert a master page to a page by right clicking on a page tab. If I misunderstood your question please let me know. 

I would like to include editable placeholders on a master page that can be changed on subsequent pages much as is done with PowerPoint templates. Or at least be able to "expand" master page items so they become editable. For example how would I use a master page to maintain a standardized title that is editable on each page using the master page?

Hi there 

Thanks for posting in the community! I recommend creating the placeholders/shapes in a Lucidchart document (without text) and then converting it to a master page (for details on how to do this please see this help center article). After doing so you can apply the master page to all other tabs in the document. In the tabs you will be able to edit/add text to those placeholders. 

Please see the below GIF on how to do this. Alternatively you could use templates and/or our locking functionality to control a shape's position size and/or style. If I misunderstood your question please let me know - and I hope this helps! 

Thank you. I just stumbled onto "Insert" menu placeholder options for "Creator Name" "Date and Time" etc. This accomplishes most of what I am looking for. I can create a "Title" on the Master using these placeholders and have the text update appropriately on each page. Would like to see those options accessible in the context menu. :)

Also will "Date and Time" or "Last Modified Date and Time" change daily or remain static after the Master is applied (I'll know by tomorrow).

Hi there 

Thank you for your response! "Date and Time" and/or "Last Modified Date and Time" updates each time you open or edit the document (depending on which option you select). You mentioned wanting to see these options in the context menu -  would you mind adding your idea to our feature request form? Ideas submitted to this form are passed on to the product development team for their consideration. 

Thanks for your request and for posting in the community!