https://pinstr.app leverages NIP33 & NIP51, and uses event kind 33888 which is a parameterized replaceable event with a list of standardized tags as below:

a "d" tag that holds the name of the board, which is also searchable,

a "header" tag that holds the name of all parameters in the board as an array,

and finally, a set of "pin" tags each holding an array of values in order of the headers array.

so each item of each pin will be considered as a value of the corresponding item in the headers array.

this way we can leverage a single replaceable event on Nostr to have the ability of making spreadsheets, two dimensional lists, and tables.