Just a quick reminder about references to the stacks project. Please refer to results in the stacks project by their tags. The tags system is explained here and here. To look up a tag you type it into the box on the query page. In a stacks project pdf just click on the name of a lemma to find its tag. Of course you can use the numbering in the current version, but if you want your references to work long term you need to use the tags.

For nerds only (if you are reading this then you are one): if you use hyperref then putting


in your latex source makes the tag 0123 in your pdf a hyperlink to the lookup page.