diff --git a/Implementing-a-Torznab-indexer.md b/Implementing-a-Torznab-indexer.md
index 371f030..0ca20d0 100644
--- a/Implementing-a-Torznab-indexer.md
+++ b/Implementing-a-Torznab-indexer.md
@@ -11,6 +11,99 @@ It's also imperative to think about how to integrate this in your existing karma
##Differences with Newznab##
+Torznab extends on Newznab on a couple of points to make it more useful. However, it is in principle backward compatible.
+
+###Torznab queries###
+
+Newznab defines the query params `q,rid,season,ep` for `t=tvsearch` and `q` for `t=search`, however not all sites support tvrage ids, and therefore would have to be queries with the q= param.
+Torznab implementations should return the supported query params in their `t=caps` response. (more on `caps` later)
+Implementations should also take care in returning appropriate responses when a query includes an unsupported newznab parameter, for example, if rid is not supported, return an empty result set.
+This is to remain backward compatibility with clients that do not query the caps.
+
+Newznab does not define `tvdbid=` and `imdbid=`, but implementors are recommended to support these if possible.
+
+```
+t=tvsearch:
+ Newznab query params: q,rid,season,ep
+ Torznab query params: tvdbid
+t=search:
+ Newznab query params: q
+t=movie:
+ Newznab query params: q
+ Torznab query params: imdbid
+```
+
+Examples:
+```
+?t=tvsearch&cat=..,..&rid=..&season=1&episode=1
+?t=tvsearch&cat=..,..&q=..&season=1&episode=1
+
+?t=tvsearch&cat=..,..&rid=..&season=2016&ep=12/20
+?t=tvsearch&cat=..,..&q=..&season=2016&ep=12/20
+
+?t=search&cat=..,..&q=Anime+Title+123
+?t=search&cat=..,..&q=Fantastic+Series+With+Episode+Title+For+Special
+```
+
+###Torznab caps endpoint###
+
+The mode `t=caps` is supposed to return the capabilities and categories of the newznab/torznab indexer.
+Implementing this mode is mandatory.
+
+The caps response for torznab is mostly the same as newznab, except for a few points:
+
+The `searching` element is normally used to specify what kind of modes (`tvsearch`,`search`,`movie`) the api supports. But torznab adds an optional `supportedParams` attribute allowing the api to specify which query params are supported.
+If the `supportedParams` attribute is not found, then it defaults to the original newznab params as specified earlier.
+
+Many torrent sites have their own categories starting at '1', it's recommended NOT to map these 1 to 1 on newznab categories but instead add 100000 to the number.
+That way it falls in the site specific range and does not interfere with the original newznab categories.
+The api should then alias all site-specific categories in one of the original newznab category.
+For example, if you have category 10 as Blu-Ray 1080p TV, then releases in that category would use the torznab api cats 100010,5040,5000 (Site-specific, TV/HD, TV).
+Any query that includes any of those numbers in the `cat=` parameter would return those releases as results.
+Of course it's also allowed to omit the site-specific categories entirely, and map only on newznab categories.
+
+Example `t=caps` response:
+```
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+```
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+
+###Torznab results###
First and foremost: Torznab indexers should return application/x-bittorrent as enclosure type:
```