```
% pandoc -f markdown -t html --number-sections
## First section
### Subhead
##### Subhead with gap
## Second section
^D
First section
Subhead
Subhead with gap
Second section
```
```
% pandoc -f markdown -t html --number-sections
## First section
### Subhead
# Higher-level section
## Sub
^D
First section
Subhead
Higher-level section
Sub
```
For backwards compatibility, we want it to work the old way,
giving numbers like 0.1, when `--number-offset` is used:
```
% pandoc -f markdown -t html --number-sections --number-offset=2,2,2
## First section
### Subhead
^D
First section
Subhead
```
```
% pandoc -f markdown -t html --number-sections --number-offset=0,2,2
## First section
### Subhead
^D
First section
Subhead
```