Suppose I have a card named "Nutella", and in that card there is content that says it contains Filberts (linking to the Filbert card). Then suppose you decide you would rather use the word "Hazelnut" instead of "Filbert".
You could change the content of the Nutella card directly; this would have no impact on the Filbert card.
Or, you could rename the Filbert card itself to be "Hazelnut". This would give you the option automatically update the Nutella card with the new name.
To change a card's name, just go to edit > name on the card's menus.
After editing the name and clicking the "Rename" button, you will be notified of any effects on other cards.
Note that it is generally safe to change simple card names, even when those cards have some special meaning in Decko. For example, the *read card is a Setting card that is used to control read permissions on Decko. But suppose you have a Spanish language site and want to rename the card's name to "*leer". In the Decko code, this card is referenced by a special codename, so renaming *read to *leer should not impact functionality.
If there are references (eg links or nesting) to the current name from other cards, you will be prompted to choose to update them or leave them as they are. If you leave them as they are, those cards will then have references to an unknown name. As is always the case with unknown names, those references will work again as soon as a card with that name is created.
Note that explicit CQL references are not yet tracked and therefore do not update automatically. So if you have an explicity search for all "Company" cards and you rename the Company card, you will need to update the relevant CQL by hand.
compound names are key to structuring cards, so managing these names is key to managing structure. It's important to understand that changing one compound name will not impact similar compound names. It will merely change how one card fits into the bigger picture.
For example, suppose you want change Filbert+history to Hazelnut+history. You can do this in exactly the same way that you change simple names (via edit > name in the menus).
But making this change will NOT change the name of the Filbert card.
Changing any card's name will automatically update any compound names of which the name is part. Changing A to Z will change A+B to Z+B.
More concretely, suppose you change the card named "Filbert" to be "Hazelnut". What all impacts does this have?
Both #1 and #2 above work in only one direction. For example, If you change "Filbert+history" to "Hazelnut+history" (or "A history of Filberts", "History+Filbert", or anything else), it will not impact the "Filbert" card. Changing A affects A+B, but changing A+B does not affect A.
Similarly, changing the content of a card will NOT affect the name of another card. This has occasionally confused Deckoers in the process of updating *structure rules.
For example, suppose you have a cardtype called Company, and the company is formatted to include a +address card. Editing the structure rule to change "+address" to "+street address" will NOT automatically alter any existing +address cards. Decko has no way of knowing whether this change is intended as a rename or the removal of one field and addition of another (eg removing +address and adding +phone). An edit of this sort only changes formatting; it won't rename or delete any other cards. It may make it appear that the +address cards have disappeared, but they're still around; they just won't show up on your Company cards any more. Decko never deletes cards unless you explicitly tell it to (and even then it really just adds them to the trash).
To make this change, you could instead rename "address" to "street address." As outlined above, this will automatically update all the +address cards to +street address.