From c0398b4ed1a98db08a8cd8506ff7218d7358cb08 Mon Sep 17 00:00:00 2001
From: fiatjaf_ <fiatjaf@gmail.com>
Date: Tue, 3 Mar 2026 22:46:53 -0300
Subject: Revert "NIP-91: AND operator for filters (Formerly NIP-119) (#1365)"

This reverts commit 7ec427190822b0c61446b678b37c86c98c9beea6.
---
 91.md     | 18 ------------------
 README.md | 12 ------------
 2 files changed, 30 deletions(-)
 delete mode 100644 91.md

diff --git a/91.md b/91.md
deleted file mode 100644
index 7ac15ae..0000000
--- a/91.md
+++ /dev/null
@@ -1,18 +0,0 @@
-# NIP-91: AND Operator in Filters
-
-Enable `AND` within a single tag filter by using an `&` modifier in filters for indexable tags.
-
-```
-filters: {
-  "kinds": [1],
-  "&t": ["meme", "cat"],
-  "#t": ["black", "white"]
-}
-// returns kind `1` events with `t` tags that have both "meme" and "cat" that have the tag "black" or "white"
-```
-
-## Rules
-
-- `AND` **MUST** take precedence over `OR`
-- Tag values used in `AND` **SHOULD NOT** be used in standard `OR` tags [`#`]
-- Any tag value used in `AND` **SHOULD** be ignored in `OR` 
diff --git a/README.md b/README.md
index e8a21f0..c094d47 100644
--- a/README.md
+++ b/README.md
@@ -98,7 +98,6 @@ They exist to document what may be implemented by [Nostr](https://github.com/nos
 - [NIP-88: Polls](88.md)
 - [NIP-89: Recommended Application Handlers](89.md)
 - [NIP-90: Data Vending Machines](90.md)
-- [NIP-91: AND filters](91.md)
 - [NIP-92: Media Attachments](92.md)
 - [NIP-94: File Metadata](94.md)
 - [NIP-96: HTTP File Storage Integration](96.md) --- **unrecommended**: replaced by blossom APIs
@@ -317,17 +316,6 @@ They exist to document what may be implemented by [Nostr](https://github.com/nos
 [marmot]: https://github.com/marmot-protocol/marmot
 
 
-## Filters 
-
-| kind            | description                | NIP                      |
-| --------------- | -------------------------- | ------------------------ |
-| `authors`       | by pubkey                  | [01](01.md)              |
-| `ids`           | by ids                     | [01](01.md)              |
-| `kinds`         | by kinds                   | [01](01.md)              |
-| `#{}`           | by indexable tag (OR)      | [01](01.md)              |
-| `&{}`           | by indexable tag (AND)     | [91](91.md)              |
-| `search`        | by search times            | [50](50.md)              |
-
 ## Message types
 
 ### Client to Relay
-- 
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