Show is a small Google Docs extension that allows to display non-printable characters within a Google Docs document. I developed it for my own use, as part of a larger project, and decided to make it available to others (for free, that is).
Around 27,000 users are using Show as I write these lines, and so far, feedback I've been receiving are ranging from “it doesn't work”, to “works like a charm - God bless you”, through “zero stars, why is it not like Word?”, “it doesn't detect my Tabs”, or “it messed up my whole precious document: I hate you!”.
With the number of Show users now growing fast, it is becoming more and more difficult for me to answer the various questions I'm receiving, so, I'll try to clarify and explain a few things in these pages, the most important ones being listed below.
While I'm keeping Show menus as international as I can (currently English / French / Spanish / Italian / German) and originally tried to make the original documentation available in multiple languages, I realize this would be too ambitious for the present pages, so, I'll stick to English here (but bear with me: I'm French).
...this for a simple reason:
Google Docs has version control.
No matter what happens, you can always restore your document back to its original state at any given time (File Menu → Version History).
This is due to a limitation in Google Docs Apps Script: Show will effectively display all hidden marks when you ask it to do so, but if text is added, you'll have to click again in order to display new marks.
Use the “Paste without formatting” function instead: you will loose possible rich-text attributes, but this is the only way to get rid of all invisible content and future headaches you'll have trying to figure out why your styles are ignored, why your Return key can no longer generate carriage returns, etc.
This advice is not particularly aimed at Show users, but at all Google Docs users, and more generally, true for all text editors.
First, regular spaces are not hidden symbols, but most importantly, Google Docs not having a native option to show hidden characters, the only solution I could use ends up being slow and ugly.
In a nutshell: don't use the “Show spaces” feature on documents that are more than ten pages long. If you want to see your spaces, use Ctrl-F (Cmd-F on Macs) and type a space : result is much better.
This work (Show add-on, content of the present page, as well as graphics) is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.