Indentation of wikitext

Is there a common consensus or even a standard for this in the TiddlyWiki ecosystem? If my question sounds weird - it’s dictated by my rusty (pardon the pun!) Python reflexes.

For code like

<$list filter="[tag[fixture]]" counter="i">
    <<i>>. <<currentTiddler>> <br/>
</$list>

how many starting whitespaces should the second line have?

  1. 0
  2. 2 (a la Lua)
  3. 4 (a la Python)
  4. it’s up to you
  5. anything else (please elaborate)

Tabs (displayed as four characters wide) are are mentioned as the choice in the TW coding style guidelines for developers and are used extensively in the core.

The problem with tabs though is that they need some plugin or workaround to use them easily, like:

So I guess that four spaces is the closest to the guidelines, if tabs are not available?

Four is a good start, because it often aligns with <$xx above, however I think the rule if there was one is readablity. There are structures including logical or nested structures where more or less spaces or tab equivalents make the code more readable. Such spaces are usualy only visible in the source editor, not in the output which means by definition their main purpose is supporting code readability, along with blank lines etc…