Dear friends, I am a novice user of the Tainacan plugin and I am learning to use it gradually. I need advices on the easiest method of creating several collections but with same set of metadata and taxonomies. I tried to use the Exporter / Importers options but could not achieve what I wanted. In simple words, I need to duplicate a collection, along with its customized metadata set and the linked taxonomy-fields.
Hello @parasmoni, welcome to our forum!
Your question arises different possibilities, I’ll try to cover them here.
The quickest way to have a set of metadata in common to multiple collections is by creating “repository-level” metadata. These are the ones that you create on the “dark-blue” sidepanel menu. Every repository metadata is inherited by all collections. If you want them to be used by most of the collections, but not every collection, you can disable the inheritance in the specific collection metadata page. Notice that “Core Title” and “Core Description” are collection-level metadata, but they already exist in every collection by default, and thus have similar behavior. The advantage of having repository-level metadata is mainly to have the metadata listed in the “Items Repository List”, where you can see and filter all your items.
Regarding Taxonomies, they are repository-level by nature. Even if you use them in a collection-level metadata, you will be feeding the values from terms that are accessible to any collection using the same Taxonomy. The great thing about this is that you can also access the “Term Items List”, a list where you will have all the items in the repository per-filtered by a term of a taxonomy, again also featuring items from any collection that uses it.
But, there is a catch… before you start creating repository-level metadata, I would argue that you need to make sure if you need more than one collection. Because essentially, a collection holds items defined by its sets of metadata. If an item has that set of metadata, it belongs to that collection and there should only exist another collection if it has a minimum set of different metadata that in fact make its items be “another thing”… If you have only one attribute that identifies an item as belonging to Collection A instead of Collection B, this “attribute” may be defined as a taxonomy metadata, one with terms “Collection A” and “Collection B”, then you will have all your items together in the same structure, but still be possible to browser them separately, by using the Term Items List.
The only exception to this last approach that just mentioned is if you need different permission level per collection… then a Taxonomy separation will not be enough, and you should probably be using different collections that inherit common metadata from the repository level.
Hope that gives you some ideas, feel free to ask any details or clarifications 
Thanks a lot @mateus.m.luna , for your very prompt and explanatory instructions. I shall follow your suggested procedure.