How to Use the "of" property in a "block" schema type

I'm struggling to find guides/tutorials relating to the "block" schema type using the "of" property? I seem to be missing a trick. Can anyone point me in the right direction? Thanks.

https://www.sanity.io/docs/block-type#of-d0f97ffa1dd9

something like this?

to really use portable text its an

array

type

of

... then add your types ... in this example that is

block

and a custom object i made called

inlineImage

Thanks for the quick response!
I'm looking at

inline

content within

block

type.
From the docs the

block

type

of

property states:"An array of inline content types that you can place in running text from the Insert menu."

What types are considered inline? I thought

string

would be one? I can't use type

span

for some reason.
The example in the docs has:

{
title: 'Rich text',
type: 'array',
of: [
{
type: 'block',
of: [
{type: 'footnote'}
]
}
]
}

But no explanation of

footnote

type.
I was hoping to inject like a placeholder. For example, you want to inject the site name without the need to manually enter it.

I tried the following:

blot.js

`{
title: 'Blot',
name: 'blot',
type: 'string',
options: {
list: [
{ title:

My Site Name

, value: 'site_name' }, ...

]}`

document.js

{
  title: 'Body Text',
  name: 'body',

type: 'array',
  of: [
    {
      type: 'block',
      of: [
        {type: 'blot'}
      ]
    }
  ]
}

ahh, i'm tracking .. i think

blot

in this case would likely need to be another type in the array, possibly even as a

reference

type, since that's what you're actually trying to do.. reference the type of

blot

Thanks that worked like a charm!
I changed it to the following:

{
  type: 'block'
  of: [
     { type: 'reference', to: [{ type: 'some_document'}] }
  ]
}