Using LibO on Windows XP.
There is an option under Options -> Language Settings -> Writing Aids called "Check spelling as you type". This is extremely useful in Writer: it highlights potential misspellings as soon as you have typed them, and you do not have to run the spellchecker manually to find them.
However, it is a real irritation having this turned on when using Calc: many formula names are highlighted as misspellings (since they are not real words), and this is an application where you are much more likely to enter abbreviated and cryptic text, which would also be highlighted. Although I have not yet used them, I can imagine similar irritations would surface in Base and Math.
Therefore we really need the ability to set this option per application, e.g. turned on in Writer, Draw and Impress, turned off in Calc, Base and Math (or any other permutation, at the user's discretion). I guess one way to show this in the Options dialog box would be still to have the set of global settings, but then also to have under each application heading a further set of settings, where each option could be 'on', 'off' or 'use global setting'. That would satisfy those users who would still want just global settings for these options.
I appreciate that there is a toolbar button to change this option, but using it changes the global option, so you have to keep switching it on and off as you switch between LibO applications. It would be really nice if this toolbar button changed the setting just for the current open document, and if different documents, even those open within the same application, could have different settings!
To disable spellcheck per document:
1. Press F11, appears Stylist pane
2. Select there "Default" style
3. Right click it, choose Modify
4. Select tab "Font"
5. Change language to [None]
Now spellcheck is disabled for document
For disable spellcheck for application for newly created document:
1. Create new template with disabled language
2. Set it as default template
File->Templates->Organize and right click on selected template, choose "Set as default template"
I recommend never change existing templates, only create new ones
Thanks for your attempt to suggest a workaround. As I am sure you realised, the issue is not about how to selectively enable/disable spell-checking (per document), but about how to selectively enable/disable spell-checking as you type (per application).
As far as I can tell, formula names in Calc are no longer considered misspellings. It seems like that was the root cause for why this feature request was made. Not sure if there is value in setting "Check spelling as you type" individually for each application. Personally, I prefer the settings to be set once and apply to all applications.
OS: Linux Mint 17.2
As the bug-creator pointed out, this also affects the sort of "cryptic" text that's commonly entered in spreadsheets (e.g., "CUST_ID"), so I'd say that it's still an unresolved issue. It *is* possible to enable Spellcheck in Writer and disable it in Calc (with the toolbar button) but those choices do not persist when exiting and restarting LibreOffice. Since it is possible to manually (and temporarily) set different modes in different applications, it seems like it should be possible to offer a per-application setting that makes the choice persist.