Sequential Auto Numbering

[Snowmanx812]

Hi, i am looking for Sequential Auto Numbering for a document i am creating.
I need the auto numbering to jump up a number at each MAIN HEADING,
I don't know if this helps & it isn't necessary, but as a constant identifier have shown:
MAIN HEADERS with a "<<"
& Sub Header with a "<"
there will be a different number of sub headers & empty rows.
Hope someone can help & thanks for looking.

Example 1.xlsx
	A	B	C	D
1
2
3		1.00	<< MAIN HEADING
4			Blah blah blah
5			Blah blah blah
6			Blah blah blah
7			Blah blah blah
8			Blah blah blah
9
10
11		1.01	< Sub Heading
12			Blah blah blah
13			Blah blah blah
14
15			Blah blah blah
16			Blah blah blah
17
18		1.02	< Sub Heading
19			Blah blah blah
20
21			Blah blah blah
22			Blah blah blah
23			Blah blah blah
24
25
26		2.00	<< MAIN HEADING
27			Blah blah blah
28			Blah blah blah
29			Blah blah blah
30
31
32
33		2.01	< Sub Heading
34			Blah blah blah
35			Blah blah blah
36			Blah blah blah
37			Blah blah blah
38
39
40		2.02	< Sub Heading
41			Blah blah blah
42			Blah blah blah
43			Blah blah blah
44			Blah blah blah
45			Blah blah blah
46			Blah blah blah
47
48
Sheet1

 

[Joe4]

Place this formula in cell B3 and copy down for all rows:

=IF(LEFT(C3,2)="<<",INT(MAX(B$1:B2))+1,IF(LEFT(C3,1)="<",MAX(B$1:B2)+0.01,""))

Proof of concept:

 

[JamesCanale]

I'm not crazy about this:

MrExcelPlayground23.xlsx
	A	B	C
1
2
3		1	<< MAIN HEADING
4			Blah blah blah
5			Blah blah blah
6			Blah blah blah
7			Blah blah blah
8			Blah blah blah
9
10
11		1.01	< Sub Heading
12			Blah blah blah
13			Blah blah blah
14
15			Blah blah blah
16			Blah blah blah
17
18		1.02	< Sub Heading
19			Blah blah blah
20
21			Blah blah blah
22			Blah blah blah
23			Blah blah blah
24
25
26		2	<< MAIN HEADING
27			Blah blah blah
28			Blah blah blah
29			Blah blah blah
30
31
32
33		2.01	< Sub Heading
34			Blah blah blah
35			Blah blah blah
36			Blah blah blah
37			Blah blah blah
38
39
40		2.02	< Sub Heading
41			Blah blah blah
42			Blah blah blah
43			Blah blah blah
44			Blah blah blah
45			Blah blah blah
46			Blah blah blah
Sheet8

Cell Formulas
Range	Formula
B3:B46	B3	=IF(LEFT(C3,2)="<<",INT(MAX(B$2:B2))+1,IF(LEFT(C3,2)="< ",MAX(B$2:B2)+0.01,""))