I was looking around for a good Chinese-Chinese dictionary and I fell upon 國語活用辭典. Google Books has many pages available here.
I noticed that they use the simplified form of 從 after almost (or perhaps always) all of the characters. Why is this? Is 从 an ancient form of 從?
Here is a screenshot of what I am talking about.
Thank you in advance for all input and help.
Hi Rypervenche, and welcome to Forumosa! 
Yes – it can be found on the oracle bones (as can a version with 彳+ 从). I believe the two were interchangeable. Some think 从 was a simplified form (simplified and complex forms of the same characters coexist in the earliest texts), but I think it may have been the original, as one person behind another does reasonably imply ‘to follow’. It also meant ‘from’ and ‘big’, as in ‘big rain’ in the OB texts.
In the context you show in the screen shot, the pattern of the first circled instance of usage dates back almost 2000 years, to Shuowen (說文解字 Shuōwén Jiézì 121 CE; you can read about that on Wiki if you’re not familiar with it). It’s a dissection of the character. If it says 从 X , Y 聲 that means that the writer is analyzing the character as containing the semantic element X and the phonetic element Y. Following that is a comment on “characters which take their sound from 奇”.
