I received a comment on my previous post to a Revit Forum page that links to a nice PDF you can download and stick on your wall – it shows the Unicode values for most of the special characters that you will want to use in Revit.

Just remember to hold down Alt, press the four numbers, then let go of Alt. The special character should then appear.

EDIT:
Direct link without login (thanks to PepaR)

Direct link to PDF (you will have to login to Revit Forum)
http://www.revitforum.org/attachments/tutorials-tips-tricks/5446d1322223838-special-symbols-characters-jr_symbols-special-characters-cad.pdf

Link to post
Special symbols and characters

In AutoCAD, you can type %%c and it will get translated into a diameter symbol.  Other control codes may be found here.

However, I have found that this method does not import into Revit correctly.

Instead, you need to use the Alt+0216 code in the AutoCAD DWG file.  When this is imported or linked into Revit, the diameter symbol will display correctly.

You can use the FIND command in AutoCAD to quickly find and replace the offending %%c diameter symbols with Revit-friendly Alt+0216 diameter symbols.

Image and video below to demonstrate:

For related information, check out:
What Revit Wants: How to add symbols to Schedules and Text in Revit

This recent post by RevitKing has a nice list of the main codes you will use:
Revit.King’s BIM coordinator/ Revit Blog: Adding Revit text symbols like (diameter)

ƒ = ALT +0131
™ = ALT +0153
® = ALT +0174
© = ALT +0169
° = ALT +0176
± = ALT +0177
² = ALT +0178
³ = ALT +0179
× = ALT +0215
Ø = ALT +0216
÷ = ALT +0247

You would likely agree that the Text tool in Revit still leaves a lot to be desired, not least of which would be some decent bullets and numbering features. No doubt most of you are using Key Schedules to get around some of these limitations when creating note blocks (as described in this PDF from an AU class).

However, are you aware that you can put symbols into Revit schedules? The easiest way to described how this works is to use the Character Map. To access the Character Map, go to Start-All Programs-Accessories-System Tools and open Character Map. I have created a link to the Character Map in my Quick Launch toolbar.

So how does this thing work? Well, let’s say you are using the Arial font in Revit. Select Arial in the Character Map. Now, have a look through all these different symbols. When you find one that you like, click on it, click ‘Select’ and then click ‘Copy’. Now, go into a Revit schedule or text box that is formatted with the SAME FONT (ie. Arial) and Paste (using Ctrl+V is easiest). There you go, you have a nice symbol to play with!!

The quicker and easier way is to use the inbuilt hotkeys. For instance, to add a ‘squared’ (little superscript 2) symbol, just hold down Alt and press the keys 0 1 7 8 (just type the numbers one after the other while holding Alt). You can find out which keystroke to use by looking in the bottom right corner of the the Character Map (see below).


There are quite a few things you can do once you know how to use this. See below for a Key Schedule I made with a ‘column’ containing a rightways arrow symbol.

No doubt you issue many PDF files to consultants, Clients, Builders and the like. Why not add a URL link to your titleblock, so that anyone receiving your PDF files can jump directly to your webpage?

 

Its as simple as adding a parameter of type:URL into your titleblock.

 

To make it even easier for you, I have created a Generic Annotation family with a URL parameter inside it. Simply load this family into your titleblock, then link the parameter from it to a parameter in your titleblock (see image).
Here is the download link:

 

Now, when anyone opens this PDF, they can jump directly to your webpage.
The URLs worked fine for me using CutePDF and Adobe Reader, but Foxit Reader seemed to have an issue parsing the link correctly.