What are these lines of code?

I see the following in other templates and I wanted to get some clarity.

?{{ .Site.Params.theme_seconds }}

I don’t know where this is being pulled from we already have .Site.Params.customCSS

I also see

.Site.Params.plugins_html

My question is why is this in the header if it’s customer html. Is is for plugins that are trying to define specific html to the head? As I wrote it, I answered my question, but would like confirmation.

.Site.Params.theme_seconds is a site parameter Micro.blog sets containing the Epoch time for when the site was last changed. This can be used for cache busting.

You’re totally correct about .Site.Params.plugins_html. Plug-ins can include arbitrary HTML into the head section. There’s also .Site.Params.plugins_js and .Site.Params.plugins_css for JavaScript and CSS.