user4220: I know about token registry, which is off-chain, but I noticed that some tokens such as HOSKY are not in token registry and yet they have logo, description, URL and coin name visible on pool.pm.
Is it possible to add extra metadata when minting the coin, such as it's done with NFTs? Also https://developers.cardano.org/docs/native-tokens/minting describes only most basic policy:
vi minting-policy
{
  "keyHash": "your_key_hash",
  "type": "sig"
}

What other keys are accepted and how do they affect the policy? Is this described anywhere in detail?

user4043: HOSKY (very, very, loosely) follows the 721 NFT metadata spec to have onchain metadata, as you can see here:
{
  "721": {
    "a0028f350aaabe0545fdcb56b039bfb08e4bb4d8c4d7c3c7d481c235": {
      "HOSKY": {
        "HOSKY": {
          "website": "https://hosky.io"
        }
      }
    },
    "copyright": "HOSKY IO; all rights reserved",
    "publisher": [
      "hosky.io"
    ],
    "version": 1
  }
}

Though this doesn't include an image, I'm unsure how they got their logo on pool.pm, perhaps this is an ad-hoc thing they arranged with pool.pm. As you can see from the onchain metadata, they didn't include enough metadata on-chain for a logo (though you could use the "image" property in the NFT metadata to facilitate this.)
To answer your question about minting policies, this is completely separate to the metadata. The metadata is just supplied (as a file input to CLI or as raw JSON) to the minting TRANSACTION. It is not linked to the minting policy, they have used a  timeLocked + pubKey all policy for minting HOSKY tokens:
{
   all: [
      {
         pubKey: "421d2150828730433df35f93088bfc223f9ab3b74ad8333c160625f7"
      },
      {
         invalidAfter: 49428890
      }
   ]
}


user1231: 


Is it possible to specify metadata for native asset on-chain?



Yes, you can add metadata for your fungible tokens.



yet they have logo, description, URL and coin name visible on pool.pm.



Not sure but maybe you're confusing HOSKY tokens:

Hoksy tokens, they don't have image, description, etc, therefore nothing is displayed on pool.pm. You can check here
Hoksy NFTs, they comply with the standard, therefore, they display an image on pool.pm. You can check here

If you see, they use different policies with different metadata.



What other keys are accepted and how do they affect the policy? Is this described anywhere in detail?



Regarding to policies, you can find more information here: Simple Scripts

4220: <p>I know about token registry, which is off-chain, but I noticed that some tokens such as HOSKY are not in token registry and yet they have logo, description, URL and coin name visible on pool.pm.</p>
<p>Is it possible to add extra metadata when minting the coin, such as it's done with NFTs? Also <a href="https://developers.cardano.org/docs/native-tokens/minting" rel="nofollow noreferrer">https://developers.cardano.org/docs/native-tokens/minting</a> describes only most basic policy:</p>
<pre><code>vi minting-policy
{
  &quot;keyHash&quot;: &quot;your_key_hash&quot;,
  &quot;type&quot;: &quot;sig&quot;
}
</code></pre>
<p>What other keys are accepted and how do they affect the policy? Is this described anywhere in detail?</p>
 4043: <p>HOSKY (very, very, loosely) follows the 721 NFT metadata spec to have onchain metadata, <a href="https://cardanoscan.io/transaction/1e0612fbd127baddfcd555706de96b46c4d4363ac78c73ab4dee6e6a7bf61fe9?tab=metadata" rel="nofollow noreferrer">as you can see here:</a></p>
<pre><code>{
  &quot;721&quot;: {
    &quot;a0028f350aaabe0545fdcb56b039bfb08e4bb4d8c4d7c3c7d481c235&quot;: {
      &quot;HOSKY&quot;: {
        &quot;HOSKY&quot;: {
          &quot;website&quot;: &quot;https://hosky.io&quot;
        }
      }
    },
    &quot;copyright&quot;: &quot;HOSKY IO; all rights reserved&quot;,
    &quot;publisher&quot;: [
      &quot;hosky.io&quot;
    ],
    &quot;version&quot;: 1
  }
}
</code></pre>
<p>Though this doesn't include an image, I'm unsure how they got their logo on pool.pm, perhaps this is an ad-hoc thing they arranged with pool.pm. As you can see from the onchain metadata, they didn't include enough metadata on-chain for a logo (though you could use the &quot;image&quot; property in the NFT metadata to facilitate this.)</p>
<p>To answer your question about minting policies, this is completely separate to the metadata. The metadata is just supplied (as a file input to CLI or as raw JSON) to the minting TRANSACTION. It is not linked to the minting policy, they have used a  timeLocked + pubKey all policy for minting HOSKY tokens:</p>
<pre><code>{
   all: [
      {
         pubKey: &quot;421d2150828730433df35f93088bfc223f9ab3b74ad8333c160625f7&quot;
      },
      {
         invalidAfter: 49428890
      }
   ]
}
</code></pre>
 1231: <ol>
<li>
<blockquote>
<p>Is it possible to specify metadata for native asset on-chain?</p>
</blockquote>
</li>
</ol>
<p>Yes, you can add metadata for your fungible tokens.</p>
<ol start="2">
<li>
<blockquote>
<p>yet they have logo, description, URL and coin name visible on pool.pm.</p>
</blockquote>
</li>
</ol>
<p>Not sure but maybe you're confusing HOSKY tokens:</p>
<ul>
<li>Hoksy tokens, they don't have image, description, etc, therefore nothing is displayed on pool.pm. You can check <a href="https://pool.pm/a0028f350aaabe0545fdcb56b039bfb08e4bb4d8c4d7c3c7d481c235.HOSKY" rel="nofollow noreferrer">here</a></li>
<li>Hoksy NFTs, they comply with the standard, therefore, they display an image on pool.pm. You can check <a href="https://pool.pm/a5bb0e5bb275a573d744a021f9b3bff73595468e002755b447e01559.HOSKYCashGrab000091146" rel="nofollow noreferrer">here</a></li>
</ul>
<p>If you see, they use different policies with different metadata.</p>
<ol start="3">
<li>
<blockquote>
<p>What other keys are accepted and how do they affect the policy? Is this described anywhere in detail?</p>
</blockquote>
</li>
</ol>
<p>Regarding to policies, you can find more information here: <a href="https://github.com/input-output-hk/cardano-node/blob/master/doc/reference/simple-scripts.md" rel="nofollow noreferrer">Simple Scripts</a></p>
