since Deflemask can do OPM, so I tried to make convertion table between Defle and VOPM (side effect, when I convert, it should be compatible to MML)

So, here is conversion table:
in-defle in-VOPM in-MML
A AR AR
D D1R DR
S D2R SR
D2 ?? ?? (tell me, D2 = SL?)
?? D1L SL
TL TL OL
RS KS KS
R RR RR
MULT MUL ML
DT DT1 DT1
DT2 DT2 DT2

Funny, I was working on a Deflemask / pmd98 comparison, which is quite similar:
http://garvalf.free.fr/index.php?page=articles_fm.en

which MML software do you target?

For my part, I think SR (Sustain Rate) is not used in DefleMask, S is for Sustain Level, but I may be wrong. Also I compare the YM2612 (megadrive/genesis) with the YM2608 (pc-98), they are not the same, but quite similar.

You can also have the deflemask specification for the instrument format: http://deflemask.com/DMP_SPECS.txt
//IF INSTRUMENT MODE IS FM ( = 1)
1 Byte: LFO (FMS on YM2612, PMS on YM2151)
1 Byte: FB
1 Byte: ALG
1 Byte: LFO2 (AMS on YM2612, AMS on YM2151)

Repeat this TOTAL_OPERATORS times
1 Byte: MULT
1 Byte: TL
1 Byte: AR
1 Byte: DR
1 Byte: SL
1 Byte: RR
1 Byte: AM
1 Byte: RS
1 Byte: DT (DT2<<4 | DT on YM2151)
1 Byte: D2R
1 Byte: SSGEG_Enabled <<3 | SSGEG


Here is a table I made:

| genesis (deflemask) | pmd98 | Name | Range |
| | | Reference number | 0～255 |
| A | AR | Attack Rate | 0～31 |
| D | DR | Decay Rate | 0～31 |
| - | SR | Sustain Rate | 0～31 |
| S | SL | Sustain Level | 0～15 |
| D2 | - | second decay rate (d2r) | 0～31 |
| R | RR | Release Rate | 0～15 |
| TL | TL | Total Level | 0～127 |
| ? | KS | Key Scale | 0～3 |
| Mult | ML | Multiple | 0～15 |
| DT | DT | Detune | 0～7 |
| AMS | AM | AMS Enable | 0～1 |
| ALG | AL | Connection | 0～7 |
| FB | FB | Self Feedback | 0～7 |

also do you know how detune works? In deflemask you can have -3 to +3. In VOPM or MML, you can select between 0 and 7 and it seems 0 means no detune. Does it mean 3 is like 3 and 7 is like -3?

Seems to be, Haven't tried out. -3 to +3 seems to be 0 1 2 3 4 5 6 7. Idk.
>which MML software do you target?
PMD.

From the YM2608 manual

, values greater than 4 detune downwards.

For DT, the 3rd bit is is used as a sign bit. So you actually have 0, 1, 2, 3, -0, -1, -2, -3.
Defle don't show the double zero (because -0=0 of course) so you can see a normal -3...3 range.

Oh.
so
0 0
1 1
2 2
3 3
4 -0 (unused)
5 -1
6 -2
7 -3